can anyone explain to me the amperage rating on esc's (higher rating vs. lower)? thanks.

the higher the number the hoter the moter u can run from my under staning of thing hope this helps

Check out this article from RCBM.

[link=http://www.rcboatmodeler.com/rb/articles/reverse_esc.asp]ESC Article[/link]

The higher the amperage rating the more power you can pull through it without damaging it.

Personally I wouldn't run anything under a 40A in a boat. If you want to really be on the safe side of things run an RC Hydros 90A unit and you'll be 99% bulletproof!

Be carefull of the ratings of car esc's, the numbers they'll tell you are way out of nowhere and are extremely misleading. Stick to a good marine esc and you'll be in good shape.

I've been going down as low as a 35A Jeti flight ESC to run a 12-cell, 700 motor, stepped monohull.
The ESC is made watercooled and runs for years now without any problems.

Only on a well set-up boat will you get away with it, if you don't get the set-up right, the thermal overload will cut in, despite the watercooling.

I agree when you say it's on the edge, but hey, if you don't have the money for those big ESC's?

Regards, Jan.