Hi Noob,

Turn limits on an ESC indicates how much current the ESC will handle before it will either shut down thermally, or go up in smoke.
A 27 turn motor will have more torque than a 17 turn one, the 17 turn motor will comsume more Ah than the 27 turn motor, hence the limits.

IMHO the "turn-limited" esc have little use for boats, unless specially designed for it.

I run electric flight ESC's in my boats and have no "turn" issues whatsoever, as long as I stay within the ESC's parameters.

Regards, Jan.