I have 4 trailers.
Two Galvanized Steel, One Steel (painted), one aluminum (2 position snowmobile). My boats are on Glavanized trailers and neither has rusted although admittedly I only put them into fresh water. The Aluminum Trailer is the greatest. Light and VERY versatile as Rick pointed out. In addition to towing two snowmobiles with it and towing around a Hobie 16 I had for a while, I use it almost every weekend for something...... getting mulch, or bringing brush to the recyling center etc. etc. It's great for carrying odd size things like mattresses too.

A friend had a steel trailer sprayed with the bedliner stuff from LINE-EX. That is one great system and completely impervious to weather I think. I will watch and see how he likes it and report back at some point.

The nice part about being a pessimist is that you are constantly being either proven right or pleasantly surprised. - George Will
"It's not that liberals aren't smart, it's just that so much of what they know isn't so" -Ronald Reagan