I TRIED THE U.S. NAVY SWIM TEST - I'm not a strong swimmer

I BROKE THE RULES BY USING A SNORKEL BUT I WOULD RATHER USER THAT THAN HAVE MY USUAL ACHING NECK. DON'T THINK IT MADE MUCH DIFFERENCE, IF ANY TO THE TIME.
500-yard or 450-meter Swim. The swim event may be conducted if facilities are
reasonably available. The swim event consists of swimming 500 yards or 450 meters in
fastest time possible. Any swim stroke and turn may be used and will only be conducted
in a standard 25 or 50 yard/meter swimming pool. For safety purposes, no more than 3
swimmers per CFL/ACFL are authorized in the water at a time.
(1) The follow procedures are provided to successfully conduct the PRT Swim:
(a) Swimmer will begin test in water. No diving starts.
(b) CFL/ACFL will announce the start as well as number of pool lengths
and associated times until Sailor has completed either 500 yards or 450 meters.
(c) Time will be recorded with a stopwatch to nearest second.
(d) Swimmer may push off from sides with hands and feet after each pool
length.
(e) Resting is permitted by holding side of pool, standing, or treading water.
(f) Sailors may use goggles, facemasks, swim caps, and/or ear plugs. Fins,
snorkels, flotation, wet suit, and propulsion devices are strictly prohibited.
(2) Swim event is ended when Sailor:
(a) Completes prescribed distance.
(b) Receives or requires physical assistance from CFL/ACFL, lifeguard, or
another person.