Hi The Old Fart
Like you I use the Hobbyking ESCs, but I think you are using the water cooled ones.
I have been using the car ones (HK-45A, HK-60A SL and HK-100A) with the program card(HK PROG-CARD).
I have not had one failure in three years.
As the car ones have an electric fan on top, cooling at slow speed is no problem.
Also moving the air around inside boat helps the motor.
I do not run water cooling on my brushless motors.
The motors I have used are B28-57-17L, B28-57-15L,3639-1100,D3548/4 1100, 3648 1450, 3025 1500, L5055 700 and the XK3674 1900.
The car ones will handle up to 4S.
My program setup is:-
1 Cutoff Voltage for 3S=10.2 and 4S=13.6
2 Start Power Percent=10%
3 Advance Timing=4
4 Run Mode=2
5 Brake Force=1
6 Drag Brake Force=1
7 Neutral Range=1
8 Initial Brake Force=1
9 Reverse Force=1
Canabus