Why Underwater Hull Cleaning Saves You Money on Fuel
By Landon Hull Diver · Updated 2026
Most boat owners think of hull cleaning as maintenance. It is — but it's also one of the best ways to cut your fuel costs. Here's why.
The Drag Problem
Marine growth on your hull creates friction — also called hydrodynamic drag. Even a thin layer of biofilm (that slimy green coating) increases drag measurably. Barnacles and hard growth make it dramatically worse.
Studies show that heavy biofouling can increase fuel consumption by up to 30–40%. That means for every $100 you spend on fuel, $30–$40 is being wasted pushing through growth that shouldn't be there.
The Math
Monthly fuel spend: $300
Extra fuel from fouled hull (30%): $90/month
Annual waste: $1,080
Regular hull cleaning costs a fraction of that — and pays for itself many times over.
Beyond Fuel Savings
A clean hull also means less strain on your engine, longer bottom paint life, better handling, and higher resale value. It's one of those rare maintenance items where the ROI is immediate and obvious.