[Mike C]

Originally Posted by Coley

Note that, in that link.... it is not intended for 'Marine Applications'.
I think part of the main reason for this is that it does not produce low end torque which most marine engines require.
I've seen guys swap out performance car engines into boats and their power dropped right off, at least where they want it (ie: 'out of the hole- go')...much to their surprise, again noting that boats (like trucks) need and want their power 'big' at the bottom end to get things moving.

Coley

Propeller boats (not jet boats) need a smooth, low idle speed in order to shift smoothly. They also need minimum overlap on the cam when they have a wet exhaust so reversion doesn't introduce water into the cylinder.