Hull Cleaning Your Boat: Your Ultimate Guide

Dec 12th 2023

Hull Cleaning Your Boat: Your Ultimate Guide

Boat hull cleaning keeps your vessel looking and performing its best. Unless you’re planning on outsourcing the job, knowing how to clean boat hulls is an essential skill for any captain worth their salt. Fortunately, it’s a fairly straightforward task as long as you have the right tools for the job and some expert guidance. We’re here to provide both.

Why Cleaning Your Boat’s Hull Matters

The hull of your boat is its direct connection to the water—like a car’s tires on the road. Over time, the hull’s surface accumulates marine growth called biofouling. That buildup can happen surprisingly fast, so boat hull cleaning is typically required every 1-3 months.

Biofouling can lead to a number of issues, including reduced fuel efficiency, reduced speed, engine overheating, block intakes, and structural damage. Regular maintenance prolongs the lifespan of your vessel and allows it to glide smoothly through the water as intended. Additionally, better fuel efficiency reduces your environmental impact.

Before you start cleaning your boat’s hull, consider its condition. Could you wait another week or month, or is it in urgent need of a scrubbing? Would dive cleaning be enough, or do you need to haul your battlewagon out of the water for a full boat hull cleaning? Paying attention to the hull’s current and changing condition will help you develop a sense of when cleaning is required.

1. Choose Your Battleground

First things first—determine if you’re going to clean underwater or on land. Naturally, your approach on how to clean boat hulls is going to be very different depending on whether you’re working above or below the surface.

2. Get Your Tools Ready

The Hull Cleaning Bundle from Top Shelf Marine Products

Minor maintenance may not require a hull haul-out if a diver goes to work with scrapers, brushes, and hull cleaning mitts from below.

Our cousin company, Top Shelf Marine Products, makes a variety of purpose-built supplies built to Fish Razr quality and performance standards. These must-have boat hull cleaning tools are incredibly useful for both basic underwater maintenance and complete haul-out haul cleanings.

If you’re working on land, you’re also going to need a big sponge and some boat hull cleaner. For fiberglass hulls with no bottom paint, On & Off from MaryKate is a great choice. Star Brite Instant Hull Cleaner is suitable for painted surfaces.

Moving forward, we’re going to cover how to clean boat hulls on land, as underwater cleaning is a very straightforward job—simply go to town with your abrasive supplies. Just make sure you’re using the correct tools. For example, our boat hull cleaning mitts come in three different coarseness levels. You don’t want to use an overly aggressive mitt for a job that only requires a gentle scrubbing.

3. Rinse the Hull

Once you’ve hauled your boat to a suitable location, the first step is giving the hull a good rinse. Some captains swear by power washers, while others prefer gentler methods. Every hull is unique, so it’s up to you to decide how much pressure you want to use. A regular hose works but will usually require more effort on your part.

Regardless of which rinsing method you use, get started as soon as the hull hits the air. The longer it sits, the harder it gets.

4. Clean the Hull

A man using Ultimate Scrapers from Top Shelf Marine Products on a boat’s hull

 The actual boat hull cleaning process is pretty simple. Use your tools to carefully remove the biofoul. It’s very important to note that buffing, scrubbing, and cleaning with too much force can damage the paint and finish. Start with a soft touch. You’ll develop a feel for how to clean boat hulls over time. For now, proceed with caution.

Ablative paint on boats that stay in the water long-term is designed to come off naturally over time, but you don’t want too much to come off when you’re cleaning. If your hull has ablative paint, be especially gentle.

After using scrapers, brushes, and/or scouring mitts to remove biofoul, mix your boat hull cleaning product with water (if necessary) according to its instructions. Wash the hull just like you’re washing a car. Use your sponge in a circular motion to wash the hull all over.

5. Rinse the Hull Again

Once you’re finished washing the hull, rinse it thoroughly with water. Finish the job by using a sponge and clean water to remove any watermarks and leftover cleaning solution.

Shop Professional Hull Cleaning Products

Now that you know how to clean boat hulls, check out our selection of top-of-the-line hull and bottom cleaning supplies, and place your order with confidence. If you’re planning on painting after you’ve finished boat hull cleaning, check Fish Razr’s Ultimate Guide to Painting the Bottom of a Boat. Shop the highest quality offshore angling gear at Fish Razr.

About Author

Les Orr is a co-owner of Fish Razr and a native of the Gulf Coast of Texas. He grew up fishing the inshore waters of the Galveston Bay system and occasionally offshore. He moved to South Carolina for a job opportunity in 1994, and his love of the offshore grew in the Charleston area. He currently lives and works in Mt. Pleasant, SC, with a wife and two young kids, 12 and 13 years old. His son is becoming quite the angler and loves going offshore to catch dolphin, tuna, wahoo, and the occasional marlin or sailfish.