Careful doing that in the marina though!Crank handles are designed to disengage from the crank shaft when the engine starts. Sockets aren't, so when the engine starts you could find yourself faced with a drill rotating with the engine, either that or a kick back. In either case, a broken wrist is about the best you could hope for.
In any case, I'd be surprised if a drill had enough torque to rotate a diesel over the compression. The starter motor uses a very large mechanical advantage to turn the engine; I don't know the numbers, but consideration of the relative size of the starter motor pinion and the flywheel suggest something like 20:1. A high revving (in engine terms) electric drill probably lacks the torque.
There's always the Moitessier approach - wrap the main sheet round the fly-wheel and then gybe!