we did clean the hull of our 1982 Maramu april 2016 using cryogenic blasting; quite common now in the industry in Europe.
- boat had been in water since april 2014, unused since april 2015, growing weeds by the bushel & great farm for oysters & mussels -
Cryogenic blasting uses CO2 gas to produce carbonic dry ice pellets blasted on the hull at low air pressure; no dirt or pollution and less agressive on gel coat resins.
cleaned all layers of antifouling paint which had been splattered on during ? ages (no record of maintenance when we boughht the boat 2016) ?
went down to gel coat layers & left them clean to survey the hull and dry out before laying on new protection (époxy coating) underwater.
reasonable price (Euros 2K Euros for a speedy process - took 4 hours (setting up, work & dismantling apparatus) to team of 2 to clean the bottom hull of the Maramu.
If available in your corner of the Oceans, I would recommend that you check industrial cleaning companies for the service - search companies or small operators working for metal, housing (front coatings), wood, stone cleaning using low pressure compressors.
Worth the cost when you gain another 10 to 15 years of trouble free hull & the extra speed from a clean & smooth hull.
fair winds & clean hulls
christian alby, Maramu Désirade VIII, Canet/roussillon