Osmosis treatment and prevention.
Prevention is the best option on the market some modern boat-building companies now have very good build procedures in place to prevent osmosis. Older vessels are usually more prone to osmosis but it can affect vessels of any age. The sooner a boat can have preventative coatings applied, the better the chance of it never developing osmosis in the future.
The severity of the work required to remove the osmosis depends on the depth and the size of the blisters.
In general, the gelcoat needs to be removed and the glass fibre dried out. Then apply a sealer coat, screed a filler to give a smooth protective surface, apply extra coats for protection and then apply the antifouling.
The above is a very quick guide there is a lot more detail, specification and information to consider.
Materials are being updated all the time and the prices are becoming more competitive.
Each yacht with osmosis is treated individually as no one case is exactly the same as another.
Talking through your requirements are free.