An alternator uses about 1 hp/25 amps output. 105 amps is about max for a single belt according to Balmar and others. Right at the limit all around but workable.
It could be wired so it can be switched off when max power is needed for propulsion or it could be installed with a regulator that allows the output to be dialed back to say 80% - that way it would run cooler as well.
Living aboard in Victoria Harbour