1: give the boat a preseason detail using top quality products to protect the gel coat, vinyl/canvas and metal(s) -- 3M* or Collinite*, 303 products**, FLINTZ or Simichrome***, etc. (a few $$ makes a huge difference; buy the best, don't skimp)
2: do not use household or non-marine specific products (AJAX, COMET, bleach, etc.)
3: have a spray bottle with a marine wash and water mix to spray things down for wash/rinse during/after fishing/cruising
4: keep up with wash/wax/detailing as necessary, so it doesn't get ahead of you (eat the elephant one bite at a time, rather than trying to swallow it whole)
*cleaner/wax for light cleaning and waxing
**for vinyl/canvas cleaning and protecting
***for metal polishing and protecting