Hull Limescale/Scale Cleaning: Removing Stubborn Crust

The hard crust known in Turkish as "kekamoz" is a layer of scale, marine-growth residue and minerals that builds up on the underwater surface and waterline over time. It spoils the look, increases drag and, if neglected, bonds to the gelcoat and becomes hard to remove.

Why does scale form?

The longer a boat stays afloat, the more weed, mussels and scale accumulate on the hull. When the antifouling weakens or the boat sits idle for long, this layer hardens and won't come off with normal washing.

How is it cleaned?

• Timely action: pressure wash as soon as the boat is hauled out — far easier to remove before it dries and hardens.
• Controlled chemical/mechanical: hardened crust is removed with a method that won't harm the gelcoat. Over-aggressive scraping thins the gelcoat, so care is needed.
• Afterwards: antifouling is renewed on the clean surface, so next season's build-up is reduced from the start.

Prevention

Regular hull maintenance and timely antifouling renewal largely prevent scale. A haul-out and annual maintenance plan keeps this build-up under control.

We clean stubborn hull crust without harming the gelcoat under our maintenance service.