Plus one to all of that.

You may need to replace your exhaust risers every couple of years. Make sure that you have a galvanized/aluminum trailer, it's hard to flush those completely and steel won't last.
Make sure that you have a good coat of high temp paint on your engine, or it will start to rust fast. There are rust inhibitor sprays that I would use instead of WD-40. Washing and flushing is the key. Expect to take almost an hour after each use.
Every couple of months, you will need to inspect your wiring. The salt spray will get everywhere and may lead to corrosion on wiring.