Super helpful to a person like me who is not "boat" savvy at all. I learned a lot watching this vid. Huge "thank you" to YOU, for sharing this very detailed explanation of how these vessels & keels, work. 👍🏽👍🏽
My Catalina 18 has a wing keel, and I really love it. Although the boat is small, it sails like a much larger boat. The fin keel gives it lots of stability, while still enhancing performance. The boat hardly heels at all, 30 degrees max, even in a brisk breeze. Another cool thing about the wing keel is that it stabilizes the boat when going through large wakes from passing yachts. When the wave goes to pick the boat up, the wing slows the upward lifting of the boat. Then, on the way back down the back of the wave, the wing keel slows or cushions the fall. I have been hit by some huge yacht wakes, and it always amazes me how stable the boat takes it. Lastly, the draft is only 2.5 feet.
An additional advantage of a centerboard or daggerboard, especially in racing, is the fact that when running BEFORE the Wind, either one can be Retracted Removing Drag as all the force of the wind is acting on forward motion with no side slippage. Also, note that the mass of a keel or board must be directly proportional to the height of the mast(s) and the sail area that it(they) carry. Our sloop had 7 tons of lead at the base of the keel because her mast towered 80 feet above the deck. sdh T.A. '67 in CT
My first boat was a 32 ft. 1971 Islander sloop - with a fin keel, and skeg hung rudder. In a blow, she had a bad tendency to round-up (dramatically). In selecting my next boat, I wanted a Modified Full keel - and went with a 35 ft 1963 Pearson Alberg sloop. The sea handling was much improved with the Modified Keel - and in a blow - she tracked much better. I would say that the Modified Full keel also gave me greater comfort - as I had previously had some close encounters with whales, and running into a crowded field of crab pot float lines - while sailing along the Baja coast during moonless nights.
Modified full keel is on my list of desired attributes. It's great to hear a first hand account. Lobster season in San Diego sounds about the same as what you describe in Baja. A mine field of crab/lobster trap floats & lines.
Sounds like you needed to reef the main first on that Islander. Nowadays, of course, with roller furling headsails boat balance is much easier to achieve. But I agree with you about the modified full keel for cruising.
When offshore, I always sailed with either the first or second reef in, after sunset. However, during an easy day of sailing - upon approaching the northern edge of Isla Cedros, off the Baja - the wind rose sharply within seconds - and she rounded up quickly - risking a broach. Luckily, I was holding the main sheet and my instinct was instantaneous - and eased the sheet. She was a might tender.
11:15. Actually, you have the movement of centerboards and daggerboards backasswards. Centerboards pivot and swing up into the trunk, whereas daggerboards generally go straight up into the trunk/case without pivoting.
at about 5min, where you present the effect of the weight of the keel i think you took a slightly wrong approach. it is not as easy as taking the forces and adding them as they all appear at different locations. you have to look at the torque the forces cause. then you see that buoyancy and the weight of the keel work together. as the boat tilts, its center of buoyancy shifts leewards since this part of the hull gets pushed into the water further, thus creating torque working to stabilize the boat. with your approach of just adding the forces as if they acted in a single point, every boat would tip over. additionally if you look at the torque you see that the weight of the keel pulls the hull down on the windward side so its working together with the buoyancy pushing it up from leeward.
The old timer who taught me to sail described it as trying to squeeze a wet bar of soap. It's gonna slip out. The idea is the keel is like the bar of soap and the wind and the water are your hands trying to squeeze it.
Sailboats are lifted by low pressure on the backside of the sail much the same as a wing. There is some aspect from the windward side of the sail the main emphasis is lift from the backside.
Again, great summary. And pretty fun logo. I think technically, the "lift" of the sail airfoil pulls the boat, like an airplane wing. I, too, am on my couch currently lowballing boat owners this winter. It sure seems to be a buyer's market, and so that some great value will be a big determinant of the boat type I finally get. As you note, as a trade off, each hull has advantages. In fact, a good generalization is : If a boat is roomy and comfortable inside, then she sails worse and is less sea kindly. (At 11:16 I think you switched centerboard and daggerboard explanations.)
Thanks for the feedback. You are spot on. I miss spoke. Daggerboard = straight up/down. Centerboard = folds like a pocket knife. I think I can annotate the video so people know at that section. As you can probable tell I'll new at this :) You are also correct. Its the lift that generates the forward force on the boat since the wind on the leeward side of the sail has to move faster due to the sail curve causing a low pressure and sucking the boat in that direction. I'll try to add another annotation to the video. Anyway, thanks for watching and I appreciate the feedback
Winter is actually the worst time to buy a boat , it may sound counter intuitive but summer is the best time to buy because there's less demand ( most people buy during the winter ) can save as much as 20 % by looking mid summer.
Occasionally I see references to the keel having its own 'lift' underwater, similar to lift seen with sails. That seems like a peculiar notion, since lift can only be generated when direction of travel conflicts with where the keel is pointing.
spelunkerd The boat will NEVER travel exactly in the direction that the keel is pointing due to “leeway” caused by the wind blowing the boat slightly sideways. This is typically 8 to 10 degrees off the intended course to leeward, thereby permitting a keel of suitable shape to generate some ‘lift’.
@@johnclarke9054 I agree, though for the most part leeway going into the doubledigits almost requires the boat to be trimmed very badly. (closed leech on the jib generating leehelm on a beamreach did it for me once but that particular sail mas made by a total incompetent so I tend to use a different one with a better cut although it is also smaller). If you venture into the topic of asymmetric daggerboards you get rift at 0 degree angle of attack or even a degree or 2 into the negatives.
aaaaaaaaaaaaaaaah i'm just looking for a fin that isn't mounted on but part 0f the boat cause i don't want the thing to fall off at any point, but thank you now i know the difference in how they operate in water
I build 1meter racing sailboats (US1M) class. The rules are VERY basic, mast height 55" , keel 14.5" , bulb weight 5lbs. 2ch radio. I have 4 different hulls, 4 mast/sail rigs that are interchangeable. ... it's always a balancing act to keep the mast vertical for effective "drive" from the sails. ( too old to crew on my friends 40' )
The sail is a vertical wing. From above it looks like the shape of a wing. Wind flowing across the sail goes on the back side and wind side. The wind that blows across the back side of the sail goes faster than the wind on the wind side thus creating lift. Yes, boats are actually getting sucked forward due to lift on the back side of the sail! The lift is a force vector perpendicular downwind to the sail and the keel prevents that "upward" lift from pulling the boat downwind. The keel and rudder(s) also create lift but their force vectors are opposite the sail force vector, thus keeping the boat from going downwind. What's really cool is if you look at your rudder and move it back and forth. Some of the rudder is in front of the axis of rotation, thus water will push on this component counteracting water pushing on the rudder behind the axis of rotation, creating force giving you power steering! So cool!! As far as a bilge keel setup...I have no idea why you'd talk about being beached? A bilge keel system is great for stability, they're actually considered passive stability systems. They greatly reduce the boats desire to roll. I would never want to beach any keel on any boat unless it's designed for that.
When a guy from a yard responded to my question "so how does a boat sail into the wind instead of being pushed back" with "the sail generates low pressure on one side that pulls it in the direction you wanna go" my young mind was blown. I'd never considered the parallel between wings & sails until then.
Here are some use cases, What is best? Long range travel, decent weathering of storms, able to navigate reefs, large enough to grow a small veggie plot on board. Basically a "life at sea" boat to serve as home. I feel making my landlubber self seaworthy is the best way to be safe from the trials to lash this world. My wealth can't be seized and my growth not stunted when I'm at sea. My desires satisfied. Indian ocean and SE ASIA islands, Solomon Islands, New Zealand, Vanuatu, Fiji, Australia. Likely place to depart Prince Rupert, BC, Canada set sail for equatorial oceanic climates that are more stable in a changing climate. Also being able to fold down the mast and keel in a fully watertight design(capsize proof) is something Im not even sure exists but would be awesome to have
The offset of less manoeuvrability is better tracking. Full keels want to go in a straight line. But for cruising the durability is the main reason I would want a full or modified full keel. I do not want to hear the crunkle crunkle sound under the boat mid Atlantic.
Big J Productions For linger distance, I think Full or modified full is the best, gives comfort, more weight and security, and with a smaller boat, I’d want some weight on it so that it doesn’t as easily get thrown around in heavy weather
@Biana Doubt that is a terrible analogy. If you own a boat, getting wet is the last thing you want. Unless you plan on sinking your boat for insurance money.
Ok, so with a properly designed keel aerodynamics could be employed to stop a boat from heeling without the need for weight. Same for slippage. It would be like having a small underwater sail.
That would only work on a powerboat, which does not rely on the wind for generating its velocity. These devices exist on many ships and large motorboats that are displacement hulls (as opposed to planing hulls). They are called "stabilizers."
Theoretically full, though there are few boats around now with true full keels. People cross oceans in all sorts of boats but most long term serious cruisers who cover thousands of miles would probably have modified full keeled boats which also tend to be older and heavier generally than modern production line boats. Older, wooden sailboats were shaped the way they were because that's what you could do with wood, early fibreglass boats simply carried on using the same long/full keel designs but gradually have evolved in to the various keel designs seen today...
Here's a few tips for constructing boats: Allow enough time. take advantage of done for you boat templates. (I discovered about these and more from Denelle boat builder website )
I have a Olympic Dolphin 23. Dagger board keel. Dagger board rusted away. No plans can't make a new one. Keel trunk in good shape. Can I build a wing keel to slip into trunk and not use dagger board anymore.
I would think it would be possible. Naturally the wings would prevent it from fully retracting but I think it could be done. Seems much harder to do though than fabricating a replacement dagger board. I'd recommend taking pictures and posting them to the "Boat Building & Builders" group on Facebook. Some really smart and experienced guys on there who can probable give you a more exact answer.
Hi, I just bought a 24ft allan wight variant (1970'), a New Zealand design. It's a bilge twin keeler. Is it as stable as more traditional keeler (rough seas, strong winds)? Thanks for this great video
I expect to sail in south atlántic frontera of patagonia falklands cae horn and beagle channel alone what kind of sailboat what kind of rigg what kind of keel do you recomiendo me?? Thank you
The keel is the backbone of the boat and is built into the boat. All fins are not keels, wile some fins are. Removable fins are not technically the keel in boats that use them. The tiny thin fast fins on lightweight racing boats are also not the keel of the boat.
HI Couch Cruiser! Great video, not too long, no too short and just on point. Do you mind if I show it on my next passage to the crew? Newbies, three days non-stop run.
Excellent article. However, technically, the mizzen mast of a yawl is aft of the rudder post and of a ketch is forward of the rudder post. In practical terms, the mizzen sail of a yawl is smaller than that of a ketch. Having owned and sailed a cutter for years, tacking a cutter isn't really much more difficult than tacking a sloop.
A catamaran will sit much higher in the water and therefore have less wet surface than a mono hull and a trimaran is a compromise between a mono and cat so it will sit higher in the water than a mono hull but not as high as a cat.
You may learn a bit from the book understanding boat design. I cant remember the formula but you relate the keel size by a ratio of sail area versus lateral resistance. Once you subtract the lateral resistance provided by the hull below waterline, you are left with the vertical area needed to be addressed by the rudder and keel. The more the keel runs the length of the boat the shallower it can be for the same area while if doesnt run much of the length it has to be deeper as exemplifed by the fin keel. You also have to ballance the center of lateral resistance so its behind the center of effort of the sails so the boat rounds up instead of down wind.
Very true. I annotated the video to try and make what I meant more clear. The boat gets sucked forward by the difference in pressure caused by the speed if air difference on each side of the sail
Hi, engineer here. Sails do redirect air to create thrust. If air was not redirected, nothing would happen. Try not to brow-beat people who know less than you, because there's someone who knows more, and will respond in kind.
Hi Philly Cheesecake Think you should see the reply to my comment from couch cruiser (the guy who made the video) He agrees with me that he did not give a very good explanation of how a sail works. He explains in his comment how the boat is sucked along by a differential in air pressure on either side of the sail and not really by a deflection of moving air creating a thrust. There is a small element of thrust as you say but it would be very inefficient means of powering the boat without the lift created by the differential in air pressure acting on the sails.
Nice and clear videos and explanations. Good Job. Keep on. However, there was a mistake regarding the vessel stability and her speed. In the horizontal position, you only get comfortable sailing. Highest velocity is achieved precisly when the vessel leans for about 45 degrees. Plain physics.
Thanks for watching and the comment. While i agree large heel angles feel faster I don't agree they are truly faster. The greater the heel angle the more you have to use the rudder to keep on course and the more you move the rudder form center the more drag it causes acting as a brake.
Also the higher the lean angle, the less sail era is exposed to the wind. The sail angle is a result of going fast in good wind, not the reason for the speed achieved.
You should have started by talking about the keels (primary) function of C.O.G. and center of effort. The function of the keel is to keep the boat centered. Ballast is also a function of the keel. Good effort though.
A noble attempt to simplify the physics of sailing, but I'm afraid there are so many misstatements it loses much of its benefit. Granted, going into the physics in detail would lose a lot of readers, but that doesn't give license to misrepresent the facts. I'd like to give the same subject a try (one shouldn't complain unless one is willing to step in), and might do it at some later date.
The explanation of the forces driving the boat is fairly inaccurate, see e.g. www.real-world-physics-problems.com/physics-of-sailing.html or newt.phys.unsw.edu.au/~jw/sailing.html - The keel type benefit triangle is just hard to make heads or tails of.
All of the sailboat keels are off keel and do not keel the sails. Lateral resistance for the sails should be ahead of the sail area effort. The mast and headsails are keeled to keel the sails. In olden times the stem to stern keel line keeled the sails . The stem should be the deepest point of the boat to have rudder control and sail power..
All this explaining about sail boat keel and heel and counter heel is caused by the designers keep making the boat with a curve under bottom and always shaping the bottom of the boat like a V. All this can be avoid for a sail boat if they make the Bottom flat and slightly rounded at the edges. With this design no keel is necessary.
Super helpful to a person like me who is not "boat" savvy at all. I learned a lot watching this vid. Huge "thank you" to YOU, for sharing this very detailed explanation of how these vessels & keels, work. 👍🏽👍🏽
OMG. Best explanation I've seen to date. So many sailors, so familiar with the effects leave out so many details. Thank you.
I very much appreciate your videos and the breakdowns. I've only just taken an eye to sailing recently but your videos give me motivation.
My Catalina 18 has a wing keel, and I really love it. Although the boat is small, it sails like a much larger boat. The fin keel gives it lots of stability, while still enhancing performance. The boat hardly heels at all, 30 degrees max, even in a brisk breeze. Another cool thing about the wing keel is that it stabilizes the boat when going through large wakes from passing yachts. When the wave goes to pick the boat up, the wing slows the upward lifting of the boat. Then, on the way back down the back of the wave, the wing keel slows or cushions the fall. I have been hit by some huge yacht wakes, and it always amazes me how stable the boat takes it. Lastly, the draft is only 2.5 feet.
You did a great job simplifying a complex subject. I learned a lot from this video. Thank you.
Awesome you can not begin to understand how much your videos help some body totally new rap their head around the sailing concepts.
I just started watching! these clips are quite educational for someone who knows nothing about sailing I've learnt alot about basic concepts thanks
An additional advantage of a centerboard or daggerboard, especially in racing, is the fact that when running BEFORE the Wind, either one can be Retracted Removing Drag as all the force of the wind is acting on forward motion with no side slippage. Also, note that the mass of a keel or board must be directly proportional to the height of the mast(s) and the sail area that it(they) carry. Our sloop had 7 tons of lead at the base of the keel because her mast towered 80 feet above the deck. sdh T.A. '67 in CT
My first boat was a 32 ft. 1971 Islander sloop - with a fin keel, and skeg hung rudder. In a blow, she had a bad tendency to round-up (dramatically). In selecting my next boat, I wanted a Modified Full keel - and went with a 35 ft 1963 Pearson Alberg sloop. The sea handling was much improved with the Modified Keel - and in a blow - she tracked much better. I would say that the Modified Full keel also gave me greater comfort - as I had previously had some close encounters with whales, and running into a crowded field of crab pot float lines - while sailing along the Baja coast during moonless nights.
Modified full keel is on my list of desired attributes. It's great to hear a first hand account. Lobster season in San Diego sounds about the same as what you describe in Baja. A mine field of crab/lobster trap floats & lines.
Sounds like you needed to reef the main first on that Islander. Nowadays, of course, with roller furling headsails boat balance is much easier to achieve. But I agree with you about the modified full keel for cruising.
When offshore, I always sailed with either the first or second reef in, after sunset.
However, during an easy day of sailing - upon approaching the northern edge of Isla Cedros, off the Baja - the wind rose sharply within seconds - and she rounded up quickly - risking a broach. Luckily, I was holding the main sheet and my instinct was instantaneous - and eased the sheet. She was a might tender.
Just found this series. I assume I a little bit less into this than when you made this series but thank you, seems very informative.
11:15. Actually, you have the movement of centerboards and daggerboards backasswards. Centerboards pivot and swing up into the trunk, whereas daggerboards generally go straight up into the trunk/case without pivoting.
I am a couch sailor as well. I learned a lot!
excellent explanations, made clear the implications of the keel varieties, It will help me a lot. Congratulations and good winds!
You did a real good break down on the types.
at about 5min, where you present the effect of the weight of the keel i think you took a slightly wrong approach. it is not as easy as taking the forces and adding them as they all appear at different locations. you have to look at the torque the forces cause. then you see that buoyancy and the weight of the keel work together. as the boat tilts, its center of buoyancy shifts leewards since this part of the hull gets pushed into the water further, thus creating torque working to stabilize the boat. with your approach of just adding the forces as if they acted in a single point, every boat would tip over. additionally if you look at the torque you see that the weight of the keel pulls the hull down on the windward side so its working together with the buoyancy pushing it up from leeward.
Daggerboards move straight up and down. Swing keels "open and close".
swing keels = centerboards
Kee them coming please. That was clear and concise with no fluff. Thanks.
The old timer who taught me to sail described it as trying to squeeze a wet bar of soap. It's gonna slip out. The idea is the keel is like the bar of soap and the wind and the water are your hands trying to squeeze it.
Well explained using lots of visuals thank you..thumbs 👍 anytime.
Excuse me, can you explain the differences between the bilge, bulb and wing keel in term of advantages and disadvantages more?
Nice videos. I notice some small jumps in a couple of your videos where you move from one image to the next.
Great education video. fantastic for novice like me. Thank you.
the longer keels (full or modified) are also better in heavy weather and will "heave to", while a fin keel may not heave to at all in heavy weather
Great and important tutorial, thnx much.
Glad you enjoyed it!
Thanks for the info. Very informative.
Great info, thank you!
Sailboats are lifted by low pressure on the backside of the sail much the same as a wing. There is some aspect from the windward side of the sail the main emphasis is lift from the backside.
Is a full keel more seaworthy than a fin keel? Can you hove to with a fin keel?
Excellent video
Again, great summary. And pretty fun logo. I think technically, the "lift" of the sail airfoil pulls the boat, like an airplane wing. I, too, am on my couch currently lowballing boat owners this winter. It sure seems to be a buyer's market, and so that some great value will be a big determinant of the boat type I finally get. As you note, as a trade off, each hull has advantages. In fact, a good generalization is : If a boat is roomy and comfortable inside, then she sails worse and is less sea kindly.
(At 11:16 I think you switched centerboard and daggerboard explanations.)
Thanks for the feedback. You are spot on. I miss spoke. Daggerboard = straight up/down. Centerboard = folds like a pocket knife. I think I can annotate the video so people know at that section. As you can probable tell I'll new at this :)
You are also correct. Its the lift that generates the forward force on the boat since the wind on the leeward side of the sail has to move faster due to the sail curve causing a low pressure and sucking the boat in that direction. I'll try to add another annotation to the video.
Anyway, thanks for watching and I appreciate the feedback
Winter is actually the worst time to buy a boat , it may sound counter intuitive but summer is the best time to buy because there's less demand ( most people buy during the winter ) can save as much as 20 % by looking mid summer.
add annotation in-video ;) nobody's reading description.
Right on! Very well explained.
Thanks for watching!
Occasionally I see references to the keel having its own 'lift' underwater, similar to lift seen with sails. That seems like a peculiar notion, since lift can only be generated when direction of travel conflicts with where the keel is pointing.
spelunkerd
The boat will NEVER travel exactly in the direction that the keel is pointing due to “leeway” caused by the wind blowing the boat slightly sideways. This is typically 8 to 10 degrees off the intended course to leeward, thereby permitting a keel of suitable shape to generate some ‘lift’.
@@johnclarke9054 I agree, though for the most part leeway going into the doubledigits almost requires the boat to be trimmed very badly. (closed leech on the jib generating leehelm on a beamreach did it for me once but that particular sail mas made by a total incompetent so I tend to use a different one with a better cut although it is also smaller). If you venture into the topic of asymmetric daggerboards you get rift at 0 degree angle of attack or even a degree or 2 into the negatives.
Thank you explaining in helping me understand more
Ditto
So when you compare speeds, what kind of metrics are you talking about. Percentage ??? NMPH ??? Can you explain ???? Cheers
great job dude, very tanks, w8 for more !
great content
What do you mean by comfort?
aaaaaaaaaaaaaaaah i'm just looking for a fin that isn't mounted on but part 0f the boat cause i don't want the thing to fall off at any point, but thank you now i know the difference in how they operate in water
I build 1meter racing sailboats (US1M) class. The rules are VERY basic,
mast height 55" , keel 14.5" , bulb weight 5lbs. 2ch radio.
I have 4 different hulls, 4 mast/sail rigs that are interchangeable.
... it's always a balancing act to keep the mast vertical for effective "drive" from the sails.
( too old to crew on my friends 40' )
The sail is a vertical wing. From above it looks like the shape of a wing. Wind flowing across the sail goes on the back side and wind side. The wind that blows across the back side of the sail goes faster than the wind on the wind side thus creating lift. Yes, boats are actually getting sucked forward due to lift on the back side of the sail! The lift is a force vector perpendicular downwind to the sail and the keel prevents that "upward" lift from pulling the boat downwind. The keel and rudder(s) also create lift but their force vectors are opposite the sail force vector, thus keeping the boat from going downwind.
What's really cool is if you look at your rudder and move it back and forth. Some of the rudder is in front of the axis of rotation, thus water will push on this component counteracting water pushing on the rudder behind the axis of rotation, creating force giving you power steering! So cool!!
As far as a bilge keel setup...I have no idea why you'd talk about being beached? A bilge keel system is great for stability, they're actually considered passive stability systems. They greatly reduce the boats desire to roll. I would never want to beach any keel on any boat unless it's designed for that.
When a guy from a yard responded to my question "so how does a boat sail into the wind instead of being pushed back" with "the sail generates low pressure on one side that pulls it in the direction you wanna go" my young mind was blown. I'd never considered the parallel between wings & sails until then.
My boat has a lead swing keel. I didn't really see that covered.
Lmao this channel is the antithesis of sailing uma
Not a bad thing, I just found it funny
Handy, thank you!
Here are some use cases, What is best? Long range travel, decent weathering of storms, able to navigate reefs, large enough to grow a small veggie plot on board. Basically a "life at sea" boat to serve as home. I feel making my landlubber self seaworthy is the best way to be safe from the trials to lash this world. My wealth can't be seized and my growth not stunted when I'm at sea. My desires satisfied. Indian ocean and SE ASIA islands, Solomon Islands, New Zealand, Vanuatu, Fiji, Australia. Likely place to depart Prince Rupert, BC, Canada set sail for equatorial oceanic climates that are more stable in a changing climate. Also being able to fold down the mast and keel in a fully watertight design(capsize proof) is something Im not even sure exists but would be awesome to have
Very informative! Thank you!!!
Very helpful. Thank you.
The offset of less manoeuvrability is better tracking. Full keels want to go in a straight line. But for cruising the durability is the main reason I would want a full or modified full keel. I do not want to hear the crunkle crunkle sound under the boat mid Atlantic.
Good overview
Where can I get that last diagram you showed? I would like a copy so I can figure out what I would like.
Which keel would you recommend for a small (26-30ft) trailer sailer intended for crossing the Caribbean twice a year?
Big J Productions For linger distance, I think Full or modified full is the best, gives comfort, more weight and security, and with a smaller boat, I’d want some weight on it so that it doesn’t as easily get thrown around in heavy weather
If you don't know, you need to sell your boat and get a new hobby.
@Biana Doubt that is a terrible analogy. If you own a boat, getting wet is the last thing you want. Unless you plan on sinking your boat for insurance money.
@Biana Doubt you can stop patting yourself on the back. You're not that smart and we all know it.
@Biana Doubt now who's triggered 😂😂😂
Ok, so with a properly designed keel aerodynamics could be employed to stop a boat from heeling without the need for weight. Same for slippage. It would be like having a small underwater sail.
That would only work on a powerboat, which does not rely on the wind for generating its velocity. These devices exist on many ships and large motorboats that are displacement hulls (as opposed to planing hulls). They are called "stabilizers."
@@OgamiItto70 - Or called "foils" which, do exist on sail boats and stop the mono hull from heeling.
So which keel would be best for ocean crossing and deep blue water sailing?
Full
Theoretically full, though there are few boats around now with true full keels. People cross oceans in all sorts of boats but most long term serious cruisers who cover thousands of miles would probably have modified full keeled boats which also tend to be older and heavier generally than modern production line boats. Older, wooden sailboats were shaped the way they were because that's what you could do with wood, early fibreglass boats simply carried on using the same long/full keel designs but gradually have evolved in to the various keel designs seen today...
Here's a few tips for constructing boats:
Allow enough time.
take advantage of done for you boat templates.
(I discovered about these and more from Denelle boat builder website )
Good way to explain this, thanks
Very helpful
I have a Olympic Dolphin 23. Dagger board keel. Dagger board rusted away. No plans can't make a new one. Keel trunk in good shape. Can I build a wing keel to slip into trunk and not use dagger board anymore.
I would think it would be possible. Naturally the wings would prevent it from fully retracting but I think it could be done. Seems much harder to do though than fabricating a replacement dagger board. I'd recommend taking pictures and posting them to the "Boat Building & Builders" group on Facebook. Some really smart and experienced guys on there who can probable give you a more exact answer.
Hi,
I just bought a 24ft allan wight variant (1970'), a New Zealand design. It's a bilge twin keeler. Is it as stable as more traditional keeler (rough seas, strong winds)? Thanks for this great video
How have you found the bilge in "rough seas"?
what do you base your knowledge on? experience, (if so how much) or reading? if so what are your sources please.
I expect to sail in south atlántic frontera of patagonia falklands cae horn and beagle channel alone what kind of sailboat what kind of rigg what kind of keel do you recomiendo me?? Thank you
BUENA suerte pedro , Navegue from pueto gallegos to rio grande and ushuaia 1987
What kind of keel too thanks
The keel is the backbone of the boat and is built into the boat. All fins are not keels, wile some fins are. Removable fins are not technically the keel in boats that use them. The tiny thin fast fins on lightweight racing boats are also not the keel of the boat.
Great videos! Thanks can you make a video about pilot house vs open ones?
Great video!!!
HI Couch Cruiser! Great video, not too long, no too short and just on point. Do you mind if I show it on my next passage to the crew? Newbies, three days non-stop run.
TheYrrinotherapy share away. I only make these for fun and with the hope someone else enjoys them too.
Excellent article. However, technically, the mizzen mast of a yawl is aft of the rudder post and of a ketch is forward of the rudder post. In practical terms, the mizzen sail of a yawl is smaller than that of a ketch. Having owned and sailed a cutter for years, tacking a cutter isn't really much more difficult than tacking a sloop.
Question for anybody out there... why are catamarans & trimarans usually faster, even though they are multi- hulls with a lot more wet surface?
A catamaran will sit much higher in the water and therefore have less wet surface than a mono hull and a trimaran is a compromise between a mono and cat so it will sit higher in the water than a mono hull but not as high as a cat.
@@maelstrom2594 Thanks for the info.
is there math to design a proper size keel for a boat like 50' 15' beam or 40' 20' beam for say speed. size weight and so on
You may learn a bit from the book understanding boat design. I cant remember the formula but you relate the keel size by a ratio of sail area versus lateral resistance. Once you subtract the lateral resistance provided by the hull below waterline, you are left with the vertical area needed to be addressed by the rudder and keel. The more the keel runs the length of the boat the shallower it can be for the same area while if doesnt run much of the length it has to be deeper as exemplifed by the fin keel. You also have to ballance the center of lateral resistance so its behind the center of effort of the sails so the boat rounds up instead of down wind.
thank you!!!
Thank you
well done
You the best
You don't understand what propels the boat. It is LIFT created by the sail, just like an airplane wing.
Thanks, one on rudders will be great too
Very clear thanks
in the beginning something goes wrong in the video
So you are saying that the sail redirects the wind and creates a thrust,pushing the boat forward. That is so not correct.
Very true. I annotated the video to try and make what I meant more clear. The boat gets sucked forward by the difference in pressure caused by the speed if air difference on each side of the sail
Hi, engineer here.
Sails do redirect air to create thrust. If air was not redirected, nothing would happen.
Try not to brow-beat people who know less than you, because there's someone who knows more, and will respond in kind.
Hi Philly Cheesecake Think you should see the reply to my comment from couch cruiser (the guy who made the video) He agrees with me that he did not give a very good explanation of how a sail works. He explains in his comment how the boat is sucked along by a differential in air pressure on either side of the sail and not really by a deflection of moving air creating a thrust. There is a small element of thrust as you say but it would be very inefficient means of powering the boat without the lift created by the differential in air pressure acting on the sails.
sails dont create thrust... they create lift
Is it just me or do his videos skip at the end of segments sometimes?
Its not just you. Its the recording method I was using. I've changed to Adobe Premiere Elements and the quality should increase a bit
I just started watching! these clips are quite educational for someone who knows nothing about sailing I've learnt alot about basic concepts thanks
Nice and clear videos and explanations. Good Job. Keep on.
However, there was a mistake regarding the vessel stability and her speed. In the horizontal position, you only get comfortable sailing. Highest velocity is achieved precisly when the vessel leans for about 45 degrees. Plain physics.
Thanks for watching and the comment. While i agree large heel angles feel faster I don't agree they are truly faster. The greater the heel angle the more you have to use the rudder to keep on course and the more you move the rudder form center the more drag it causes acting as a brake.
Also the higher the lean angle, the less sail era is exposed to the wind. The sail angle is a result of going fast in good wind, not the reason for the speed achieved.
You skipped the traditional Dutch Sailing Barge, with no keel.
Its pronounced luard though. I don't know why, and it confused me a lot.
You might have mentioned bilge keels. 😎
You should have started by talking about the keels (primary) function of C.O.G. and center of effort. The function of the keel is to keep the boat centered. Ballast is also a function of the keel. Good effort though.
A noble attempt to simplify the physics of sailing, but I'm afraid there are so many misstatements it loses much of its benefit. Granted, going into the physics in detail would lose a lot of readers, but that doesn't give license to misrepresent the facts. I'd like to give the same subject a try (one shouldn't complain unless one is willing to step in), and might do it at some later date.
I'm looking forward to your more detailed explanation.
The explanation of the forces driving the boat is fairly inaccurate, see e.g. www.real-world-physics-problems.com/physics-of-sailing.html or newt.phys.unsw.edu.au/~jw/sailing.html - The keel type benefit triangle is just hard to make heads or tails of.
Gary Casey As a keen sailor and having designed and built a boat my self, your comments are spot on. Not to mention, the vectors are drawn improperly
great vid thanks
All of the sailboat keels are off keel and do not keel the sails. Lateral resistance for the sails should be ahead of the sail area effort. The mast and headsails are keeled to keel the sails. In olden times the stem to stern keel line keeled the sails . The stem should be the deepest point of the boat to have rudder control and sail power..
Force on boat and direction of travel are reversed.
No they aren't.
All this explaining about sail boat keel and heel and counter heel is caused by the designers keep making the boat with a curve under bottom and always shaping the bottom of the boat like a V. All this can be avoid for a sail boat if they make the Bottom flat and slightly rounded at the edges. With this design no keel is necessary.
thats called a center board not a keel. The keel is basically the backbone of the hull
Wrong, the boat is not faster when upright, many designs are fastest when heeling 15-20 degrees. Maybe wait to instruct others til you know the stuff.
3:00 uhhhhhh forget about lift?
The editing keeps cutting you mid-sentence
i keel you!!!
Great, didnt waste time
Tahnsk great video, great information. But the editing is not that great, seams like you cut you self short severel times
agree with jvcoulter
we have keels primarily for lift.
don't post unless you have the correct facts
Vcv
The keel does not "force" the boat in any direction.
Chip
That's actually a horrible explanation of the effects of wind on sail, you should read up on airplane wings it would help ... j.s.
The description says you misspoke @11 min. Dude, you fumbled, bumbled, and misspoke through the whole video.