At least rinse the boat after coming off the water. Keeping something clean is much easier than bringing back finishes dulled/scratched by ground-in dirt and goo.
I rinsed every few days, cleaned weekly, detailed quarterly and that kept my 42' sedan looking new into her 30's.
It could take up to 8 hours to deep clean the boat, but a rinse was 20 minutes. A quick scrub (and dry) was a little over an hour for one person.
My favorite cleaners include
SeaPower cleaner wax
Davis Fiberglass stain remover gel
BonAmi cleanser, Barkeepers Friend (has oxalic acid).
Always flush with lots of water and keep things waxed.