How to Clean a Boat Exterior

Published on August 19, 2022


Boat ownership comes with chores, so here are some tips on fiberglass boat maintenance to keep your Sea Ray looking sharp.

Whether it’s a mid-summer facelift or a late-season full fiberglass boat detailing, an organized chore checklist and a ready supply of cleaning products will give your boat the royal treatment. 

Hull and deck cleaning 
Salt crystals form prisms on surfaces and amplify the sun’s rays that burn the surface so start with a thorough washdown of the hull and deck with lots of soap and fresh water. Give the hull a good scrub all the way down to the waterline. Get to the root of rust marks around metal attach points, waterline yellowing, and exhaust stains with FSR gel. Eliminate racing stripes from imperfect dock landings with Starbrite’s Black Streak remover. 

Once clean, polish an oxidized gelcoat hull with a polishing compound from Meguiars or 3M and then seal the shiny finish with a wax from either manufacturer. A good wax not only keeps a boat protected, it makes it easier to clean and maintain. Bird droppings, fish goo and other stains tend to stick less to wax. For quick touchups, one-step cleaner waxes work as well.

Below the waterline, check your bottom paint that keeps marine growth (both hard and soft) off the hull. For boats kept in the water year-round or for the whole season, antifouling paint will need to be refreshed periodically. Hard and ablative paints from makers such as Petit, Interlux and others are used depending on the water temperatures and conditions where you boat. Bottom jobs begin with a thorough pressure washing, masking and then painting. Most work is done by boat yards.

On deck, tackle scuff marks with Magic Eraser by Mr. Clean. On non-skid surfaces, Thetford’s UltraFoam Deck Cleaner gets into the uneven spaces to tackle mildew. Don’t forget that gelcoated deck surfaces need the same polish and wax treatment as the hull to look their best.

Touchups may be needed for woodwork on the cockpit table or trim. Natural teak may need to be scrubbed with a product like Teak Brite and can be treated with oil or a finish like Cetol, but these may streak down a gelcoat surface if in close contact. Varnish is the classic finish but requires washing, sanding or scuffing, and painting with a marine varnish of which many are available. Choose a good brush or you’ll have bristles in the finish.

Cleaning metal fixtures and finishes on your boat  
Check for rust on stainless surfaces like grabrails or stanchions because the metal is called “stainless”, not “stain-free”. Always wash metal surfaces with soap and water before polishing with a product like Prism Polish or Flitz. For more serious jobs, Bright Boy works but is more abrasive so keep it away from brass or chromed surfaces which can fog. Terrycloth towels work for wiping and polishing but the loops in the material can scratch delicate surfaces and tend to remove wax. Try microfiber cloths and mitts for a streak-free finish.

A job well done
Caring for a fiberglass boat isn’t hard but it does take organization, time, elbow grease and a few helpful products. A weekend spent on your Sea Ray boat maintenance will leave you feeling good about a job well-done and you’ll rest assured that she’s ready for cleaner cruising the rest of the season. 


This is for general information purposes only. Your use or reliance on any of the information in this Blog is solely at your own risk. Under no circumstance will we have any liability for any loss or damage of any kind incurred as a result of the use of any of the information provided.

Options and features mentioned subject to change. Please confirm availability of all accessories and equipment with an authorized Sea Ray dealer.

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