I have used Sonihull on my last two Southerly yachts and I have found the results to be more than acceptable. I use Sonihull in combination with Cucoat and applied together there is very little growth to remove. After having had my antifoul paint removed on a section of my hull, by another yacht, I found that bare gelcoat did allow some encrustations, but these were easily removed without the need for physical scraping off. The point is. Raw sonihull does allow encrustations but the Little buggers cannot attach securely Not Enough to require scraping. A combination is the most ideal for a pleasure yacht, but you will be happy with the Sonihull results. My Southerly has been in the med and the boat has not moved since September 2019.