My experience of larger engines getting dunked are that they can easily be got running again (except newer motors will need new ecu) but best get shot of it asap. It's once the motors dried out that the real problems start. Ignition stator starts corroding, electric motors eg trim pump etc pack up, moisture creeps up the inside of all your wiring insulation causing resistance, bad connections etc. There will always be a tiny bit of salt left in the motor no matter how hard you try, this invariably ends up at the bottom of the powerhead, right where the bottom crank bearing is so that'll start rattling it's head off after a few hours.
You often see motors that got wet for sale, they did this that and the other and it all works fine, bargain? No, you'll pay in the long run
Do I sound slightly bitter there?!