Cleaning my bottom

Used 5 bottles of air so far, but very hard to get all shit off...  Need to get some fresh anti fouling on soon, because it grows to fast now, anti fauling of 2 year ago was not very good..

Keel and rest of bottom was painted with black anti fauling...  trying to scrape all white shit off but inch by inch, but also black paint is off..  primer underneath was/is yellow and shows almost 50% now..