Re: 1958 18hp fastwin electic start
Saltwater is a nightmare unless you do constant maintenance on the motor, trailer, and boat. The motor has to be thoroughly flushed with fresh water each time it's used, and the boat and trailer need to be completely washed down also, with soap and water. I used to buy WD-40 by the gallon and spray the outside of the powerhead and every exposed nut and bolt on the engine. It has lasted 40 years and still runs well (the first 27 were in saltwater), but it really shows when you look at the engine.
I used to take my 13 foot Whaler 8-10 miles offshore in Fla, but it was only in perfect weather conditions, early in the morning before the thunderstorms blew in. I also have an "unsinkable" boat, 2 engines, 2.5 gas tanks, two batteries, a VHF radio, a lot of flares, and a float plan. It was also fairly busy where I was at.