Ceramic coating a saltwater boat (gelcoat)

The protocol

1. Wash thoroughly with pH-neutral soap.
2. Chemically decontaminate (iron remover); clay only if the paint feels rough.
3. Optional: a light polish first — on a low-mile car the extra clarity is worth the hour.
4. Coat: These directions are for Hydro Silk, the pad-applied wipe-on coating this protocol uses as its example — other products' tools and flash times differ, so follow your bottle. Prime the pad with two full pumps, pre-dab ~2.5 ft sections, spread thin and even, dwell 5–30 minutes, buff off. Keep dry 8 hours; no washing for 3 days.
5. Maintain: pH-neutral hand wash; no brush tunnels; a silica-safe detailer between washes.
6. Reapply: every ~4 months for this profile.

UV is the clock on an outdoor car: expect hydrophobics to fade at the front of the range and plan the reapply, not the funeral.

Specific to this setup

Coat topsides and gelcoat above the waterline only: prolonged immersion defeats consumer coatings, and slip-kept hulls fail fastest below the line.

The honest marine baseline: owners report shorter coating life on salt water than any car sees — budget the reapply, and rinse salt off after every outing.

Sources: goshineco.com