What Does a Pilot Chart Have to do with Marine Navigation?

When you hear the word pilot chart you probably think of something to do with aviation. Not so.
Some Links to Check Out:
Cornell's Ocean Atlas - amzn.to/3aqHX1n
World Cruising Routes - amzn.to/3s3LbxT
Free Pilot Chart Download from USA Government - msi.nga.mil/Publications/APC
Printed Pilot Charts (Maryland Nautical) - mdnautical.com/501-atlas-of-p...
Maury Wikipedia Page - en.wikipedia.org/wiki/Matthew...
Moitessier (Cape Horn) - amzn.to/3aurFol
Moitessier (Long Way) - amzn.to/3puxtm6
Pilot charts are tools for nautical navigators that are still valid today. Pilot charts exist in a few different forms, but they all synthesize data including weather, oceanography and other tidbits into monthly averages for all major ocean basins in the world.
In the United States, they are published for free download by the National Geospatial Intelligence Office, but you can find printed versions on various websites, or you can find private versions such as Cornell’s Ocean Atlas.
Accumulations of ocean data have existed as long as people sailed on the water; many have deep cultural roots in storytelling and tradition, but one of the first westerns to synthesize this data into a modern form is Matthew Maury, a leader in Oceanography in the mid 1800’s.
Maury is a fascinating character if you want to take a deep dive into oceanographic history, but he realized that accumulations of ship logs would be helpful for other mariners to reduce transit times and be better prepared on the ocean, which is still true today.
The modern pilot charts are broken into monthly pages which give all kinds of great information. For example, it lists average ice extent, storm tracks, and ocean currents - all helpful things to know when planning a voyage.
One of my sailing idols, Bernard Moitessier, used the gale information as he planned some of his longer sailing voyages and made a game of staying in the area where there are zero percent chance of gales in a given month.
One hazard of the pilot charts is that they do rely on historic data accumulations, and mariners generally try and avoid areas of bad weather, so there might be less data for particular regions. Another hazard is that the ocean and atmosphere are demonstrably changing over time, so historic data might not portend future conditions - for example hurricane season in the North Atlantic is expanding a bit. Finally, the charts are not regularly updated - hence commercially equivalent products such as Cornell’s Ocean Atlas, which does have more recent data.
But for both commercial navigators and recreational sailors and boaters making long distance voyages, the Pilot chart is a great tool to keep in mind. It can show you typical wind conditions and wave heights that can allow you to better plan a voyage at sea.
For example, if I was a sailing vessel interested in transiting from San Diego to Honolulu, I can see the best time to do that is in April and that I will have a favorable wind and current and avoid tropical storms. But the reverse journey will be a challenge and likely mean I have to sail quite far north to have a favorable wind and current, so I need to consider my timing carefully.
I’ve included a few links here if you are interested in more about Pilot Charts, but at the very least download one for free and check it out!

[@alexk.official7315]

Nice , another information that they didn't teach us. Appreciate it Chris.