The short answer: rinse your boat with fresh water as soon as it's out of the water, wash the hull, deck and trailer with a salt-removing detergent, flush the outboard or jet ski cooling system, then dry it and protect the metal. Doing this after every saltwater trip is what stops salt turning into corrosion, dull gelcoat and seized fittings.
This guide covers the full routine we recommend for tinnies, fibreglass boats and jet skis, and what to use at each step.
Why salt is the real enemy
Salt water doesn't just leave a white crust. As it dries, the salt crystals attract moisture back out of the air. That keeps metal fittings, trailer springs, outboard leg components and electrical connections damp and corroding long after you've packed up. On gelcoat and paint, dried salt dulls the finish and scratches when you wipe it off dry.
A plain freshwater rinse helps, but it doesn't dissolve dried salt deposits. That's why a dedicated salt-removal wash makes a difference.
What you'll need
- Salt Wash: a concentrated pH-neutral detergent that dissolves salt and mineral deposits. Safe on paint, gelcoat, fibreglass, aluminium, stainless, plastics, rubber, glass, vinyl and chrome.
- Engine Flush: for flushing salt from outboard and jet ski cooling systems.
- A foam gun: the Captain's Musket runs on a normal garden hose, so you don't need a pressure washer.
- A soft brush on a pole: our marine brush heads and telescopic pole reach hulls and cabin tops.
- A drying towel: the Big Cham chamois or Big Mike.
- Captain Seal Lanolin Spray for metal fittings and the trailer.
Want it all in one box? The Boat & PWC Replenish Kit has Salt Wash, Engine Flush, All Purpose Cleaner, lanolin spray, Final Touch, towels and a Big Cham.
Step 1: Rinse straight away
Rinse the hull, deck, trailer and outboard with fresh water before the salt dries. Work from the top down. Pay extra attention to the trailer: springs, rollers, brake components and the winch are usually the first things to rust.
Step 2: Foam and wash with Salt Wash
Fill your foam gun with Salt Wash at the dilution on the label and foam the whole boat, bottom to top. Let it sit for a couple of minutes (out of direct sun if you can) so it can dissolve the salt, then work over the hull and deck with a soft brush. Use a medium or hard brush head on non-skid decks.
Step 3: Flush the engine
Salt left inside an outboard or jet ski cooling system is a common cause of overheating and corrosion. Flush it with fresh water and Engine Flush after every saltwater run, following your engine manufacturer's flushing instructions and the dilution on the Engine Flush label. The Engine Flush Kit pairs Engine Flush with the Captain's Musket. Step-by-step: how to flush an outboard motor.
Step 4: Rinse thoroughly
Rinse all the detergent off, top to bottom, including inside the trailer frame.
Step 5: Dry, then protect
Dry with a chamois or microfibre towel to stop water spots. If you have hard-water spots on glass or gelcoat, Hydro Spot dissolves them. Then:
- Spray metal fittings, the trailer and battery terminals with lanolin spray. It leaves a water-resistant barrier that helps stop corrosion.
- Add gloss and water beading with Final Touch ceramic detailer, or wash with Boat Wash & Wax next time.
The details: vinyl, clears and glass
- Seats and vinyl: Marine Vinyl Cleaner, then Marine Vinyl Protectant. Or get both in the Sweet Seats kit. See how to clean boat seats.
- Clears and Strataglass: the Captain Clears kit. Never wipe clears dry, because salt scratches them. See how to clean boat clears.
- Windscreens: Glass Cleaner, then Duck Off so spray beads off.
- Bilge: Bilge Cleaner for oil and grime.
- Waterline stains: Hull Cleaner for yellowing, waterline stains and light rust on fibreglass and gelcoat.
How often should you wash your boat?
After every saltwater trip: rinse, wash with Salt Wash and flush the engine. Every few trips, or monthly in summer, do the full detail: vinyl, clears, lanolin on fittings and a protective finish.
FAQs
Can I just rinse with fresh water?
A rinse is better than nothing, but plain water doesn't dissolve dried salt deposits. A salt-removal wash does.
Do I need a pressure washer?
No. Salt Wash and Engine Flush both work through the Captain's Musket on a garden hose. A pressure washer speeds things up on big boats.
Is Salt Wash safe on aluminium boats?
Yes. It's pH-neutral and safe on aluminium, gelcoat, fibreglass, paint, stainless and chrome. For restoring dull, oxidised bare aluminium, see Aluminium Cleaner.
What about jet skis?
The same routine works for jet skis. Flush the cooling system after every saltwater ride. See our jet ski cleaning products.
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