Saleens7 - - - the batteries I use in my donzi are twin 7 cell NiMh stick batteries wired in series to equate to 16.8 volts. There are many alternatives on powering the boat - - I recommend reading through this thread or the similar threads on rcgroups. Each method has its benefits and drawbacks, and I came to my current powering method from trial and error.

Kmot - - - good points. I am already prepared for sealing the motor vents prior to installing the cooling jackets. I have not ruled out installing the brush cooling. First I will see how the cooling jackets perform, then I will consider further cooling if need be. Last Thursday I practically burned my fingers on the motors - so I am taking action.