With the new v2.5 Cape I see that you are using 2 pins for +vcc and 2 pins for grounds. I know that each pin on the 25pin connector can handle 5A so we could pass 10A through the two +VCC pins. What I don't know is how much current will be pulled from the batteries with all three motors running at full speed. The thrust charts done on the props indicated up to 9A on each motor could be drawn from the Battery. What has your testing shown for the current draw on the ROV in a max'd state? I will be using 4 Motors so the current draw will be higher but I will have to use other pins that may be available to source power to my 4th ESC so that should not be a problem.
The second Question is about wire. The DB25 can handle 20 Gauge wire and I was wondering what gauge wire you are now using on the OpenROV. Does the 18 gauge wire fit on the connector or did you switch to 20 gauge?