The Skipper's Blog

Ask The Skipper
Views Counter

Cleaning the bottom after VS721 Bottom Coat application


David Kessler asked:

I purchased the shiny boat kit. If the marina applied VS721 bottom coat in May, which cleaner would remove algae and fresh lake water stains after 6 weeks in the water without removing the bottom coat wax?




For your convenience, I’ve highlighted the hyperlinks. Click on the hyperlink to get more information about the selected product.


You should be able to remove fresh water slime and algae by just wiping it off with a sponge or Marine Power Mitt, if it’s still wet. Many boat owners do this while the boat is in the water by taking the boat to a sand bar or shallow beach and using a snorkel to get under the bottom. If the boat is hauled and the algae has dried, you can try wetting it with a hose and spraying on some Boat Clean Plus to penetrate and break the bond between the boat bottom and the marine growth so it can be washed away. If it’s still on the boat, then I would recommend using Green Genie, although this will remove some of the surface VS721. If you do this two or three times, you will have to re-apply one booster coat of VS721.

Stains are another matter. They can be caused by many different materials in the water. Some are superficial and can be removed as above, while others are indelible and will stain the VS721 and anything else in the water. If the Green Genie doesn’t remove it then you will need to scrub the bottom clean with Boat Scrub and a Marine Power Mitt. This will remove the VS721 and will need to be re-applied. If water staining is a problem in your lake, I recommend that you live with it until the end of the season and remove it then. In some lakes it’s just a fact of life and you need to learn to live with it or go crazy fighting to keep your boat bottom clean. The good news is that the stain will be on the VS721, which you can strip off, rather than penetrating into your gelcoat, making it much more difficult to remove.

Staining can be organic or inorganic and the most common causes are tannin in the water or industrial pollutants, but there can be other causes.

Thanks for your question

Captain Aurora
Richard Kittar

The Skipper Recommends:
More Info
More Info
More Info
More Info
More Info