I feel real bad for you guys, the topic was about Aluminum I think, don't think my little aluminum boat had any special kind of alum. and alum doesn't rust so those replies aren't directly applicable but I do get the reasoning.
Thousands upon thousands of cars and pickup truck go axle deep into the salt dozens of times every year, I don't ever hear about them rusting out losing their brake lines, tail lights, etc.
I own at the "sea"shore (waterfront) have an all aluminum car, and have zero problems. Sorry you all have been having such a rough time of it.