you shouldn't put a steel or aluminum bike on a boat like that it will be destroyed in short order. I would find a bike like the Bridgestone mentioned or some other stainless steel, or titanium frame. If you have no choice than you need to coat the inside of the frame and fork with either JP Weigle's Frame Saver or BioShield T-9, or ACF-50. Then while the seat post is removed coat the inside and the post with a thin layer of waterproof grease, some will ooze out when you reinsert the post simply wipe it off, and do the same for the bottom bracket threads, water bottle bosses threads, etc. Get a head set external seal made by Lizard Skins and put it on after the waxing explained below. Then give the bike several good external wax treatments with either Mothers California Gold, or Mequiar's NXT, then use a spray wax from either of those two brands and just hose the entire bike without wiping it off (I would do the rims too BUT you'll need to wipe down the brake surface of the rim with a cloth dampened in a mild solvent before you ride or you'll go weeeeeeee as you crash!)