What is boat careening?

Boat careening is the maintenance of the underwater part of the hull. It includes removing marine fouling, inspecting the hull, carrying out small repairs where needed and applying antifouling protection when the surface and sailing programme require it.

It is not only a cosmetic operation. A fouled hull creates drag, increases fuel consumption and reduces performance. Careening also makes it easier to detect cracks, gelcoat damage, early osmosis or an anode that is too worn.

When should you careen a boat?

Most boats are careened once a year, often before the sailing season or before a long period afloat. The right frequency depends on the sailing area, time spent in the water, water type, antifouling condition and the amount of fouling observed.

In warm or heavily fouling waters, the hull can get dirty faster. A boat wintered ashore or used occasionally may require lighter work, but checking the hull, anodes and appendages remains important before returning to the water.

Where can a boat be careened?

Careening must be carried out in an area designed for this purpose, usually in a marina, boatyard or technical area. Wash water, sanding dust and antifouling residues must be collected to avoid polluting the environment.

A slipway, beach or unprepared area is therefore not suitable. Before lifting the boat, check the marina rules, lifting options, working times, water access and specific instructions for sanding or painting.

What equipment is needed to careen a boat?

You need cleaning tools, surface preparation equipment, personal protection and application accessories. Good preparation prevents delays while the boat is immobilised ashore.

For application consumables, marine paint brushes, rollers and masking tapes should be selected according to the surface and product used.

How do you clean the hull before antifouling?

Cleaning should start as soon as the boat is lifted, while fouling is still wet and easier to remove. Pressure-wash the full hull, paying attention to the waterline, rudder, keel, drive, propeller and areas where shell growth gathers.

Keep enough distance to avoid damaging the gelcoat or a sound existing antifouling layer. Remaining organisms can be removed carefully with a scraper. If the old layer flakes, powders or creates heavy build-up, plan more thorough preparation before repainting.

What should be checked while the boat is ashore?

Careening is the best time to inspect parts that are normally underwater. A clean hull helps reveal surface defects, corrosion points, abnormal play and wear parts to replace before relaunching.

The marine anodes and hull anodes categories help you prepare replacements when wear is advanced.

How do you prepare the hull before painting?

The hull must be clean, dry, stable and properly degreased before a new coat is applied. If the old antifouling adheres well, light wet sanding may be enough. If it flakes or forms unstable layers, remove the affected areas first.

Impacts, deep scratches and chips should be repaired before painting. Marine-grade filler or resin may be required for local defects. The waterline is then masked cleanly to obtain a neat finish.

If you need to remove an old coating, the DAM Marine guide removing boat antifouling explains which methods to use according to the condition of the surface.

How do you apply antifouling after careening?

Antifouling is applied to a dry, prepared hull that is compatible with the selected product. Always follow the manufacturer's instructions for temperature, number of coats, possible thinning, time between coats and maximum time before launch.

Use a roller on large areas and a brush around through-hulls, rudder, keel or drive. Areas hidden by supports or lifting pads must be finished when the boat is moved slightly or just before launch, depending on the yard organisation.

To choose the right product, see the boat antifouling category and the DAM Marine guide how to choose the right antifouling for your boat.

What mistakes should be avoided during careening?

The most common mistakes come from rushed preparation, poor product compatibility or insufficient checks before launch. Careening should be methodical, not just a coat of paint over a dirty hull.

Do not paint anodes, incompatible transducers or parts that require specific products. Do not dry-sand without suitable protection. Do not relaunch before the manufacturer's drying time. Do not forget areas hidden by supports.

How much does boat careening cost?

The cost depends on boat size, marina, lift-out, storage ashore, hull condition, products used and whether you do the work yourself or use a professional. There is no single price for every boat.

Main cost items include lift-out and relaunch, yard space, cleaning, abrasives, antifouling, application accessories, anodes and repairs. To estimate paint quantity, use the DAM Marine guide calculating the required antifouling quantity.

What should be checked before relaunching?

Before relaunching, check that anodes are fitted, support areas have been finished, masking tape has been removed and drying times have been respected. Also check seacocks, valves, transducer, shaft seal, drive and propeller.

Once afloat, stay alert during the first minutes: no water ingress, correct valve operation, normal engine behaviour, no unusual vibration or noise around the shaft line or drive.

Boat careening FAQ