R/C Naval Combat

Adjusting the end points in your transmitter will reduce the speed.

Is there a way to do that from the beach. I need a computer to do that for my radio.

what radio do you have? if it is computer interface only, that is one of the problems with the "computer interface only"

Alex, if you're using one of the HK 2.4ghz radios that can only be adjusted from a computer, there is a way you can adjust your speed without a computer. You can get a servo stretcher and use that to adjust your throttle.

http://www.servocity.com/html/180o_servo_stretcher.html

A servo stretcher extends the range of motion on servos, but both end points are adjustable. This allows you to adjust your ESC's throttle without using your radio. The servo stretcher does need to be waterproofed, however.

Easiest, bring a laptop to the pond. Or an inexpensive netbook. You can pick them up for $200 or less.

You can also do it with several trips to the bench for testing, of course. Adjust by best guestimate (say, go to an EPA fo 80%) and see where you are at the pond. If too slow or two fast, take next guess by how close you were. Might take 3-4 trips to "dial it in". Once you are close, you might be able to your manual trim to adjust a bit to perhaps fine tune it and read the offset when you get back to see how much you need to add or subtract.