RE: Radio in Boat problems??
'dookie',
My first thought is that the receiver or associated wiring (servos, etc) is getting wet, but I'd think you've already checked for that. Next thought is how/where is the antenna? If it's in the hull, the water may be attenuating the signal enough to cause a loss of control. I'd also think that the antenna would have to be well 'down' in the hull for that to happen?
Loss of control is usually associated with loss of signal, or the receiver is 'confused' by more than one signal (or in some cases just too much signal!).
It seems like the receiver is 'defaulting' to a 'full throttle' and 'full left turn' state, so try disconnecting the receiver's antenna, collapse the transmitter's antenna, and see if this 'default' state is also true for when it's 'on land' (is it really the 'default' state?). You may have to back off some distance to make the signal at the receiver 'small' enough. If it happens on land, then I'd think it's happening because of a loss of signal so getting 'more' antenna 'up out of the boat' should help or 'cure' it. (I'm reaching for 'straws' here, so take it for what it's worth.)
Some times you 'can't see the forest for the trees', so why not have someone else check things out? (I've ~<never>~ missed something obvious like that! Wanna buy a bridge?LOL)...
- 'Doc