I am replacing all the hardware on my trailer as it goes in salt water and some of the keel roller bolts appear to be disintegrating. I ordered 316 stainless steel for all the nuts, bolts, and washers (flat and lock), but I noticed that what I pulled off were these heavy pyramid washers. I ordered some of those but I am undecided as to what would be better. The pyramid washers will be galvanized but I think they are very thick. Any thoughts on what would be better?