Take away one of the following light, oxygen, water and food and the weed dies. So putting a tarp under the hull and tying it off around your RIB might just stop the light.
Let us now if it works?
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Andy
Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hmmm. You'd be creating a fairly dark, oxygen poor (assuming limited water transfer) environment. I wouldn;t be surprised if you stopped the growth that normally happens, but accellerated growth of some other organism.
A black bag over an outdrive leg is supposed to do the trick. I always hauled out every four weeks and jet washed the thing, it kept it perfectly.Leave it for six weeks and it was a mess.