Every 6-8 weeks, if I can I like to get in and give the hull under the water line a bit of a scrub to remove any growth.

I use “Coppercoat” martini anti-fouling, which is very effective indeed, but always good to get in and give it a “dust down”.

I built my own hookah surface air breather, which is basically a 30m breathing air hose with a regulator on one end, plugged into an oil free electric compressor on the other.

I have tried cleaning using my sub aqua tanks etc. but because it is quite a physical task, you go through a tank of air in double quick time!

Also, the mass of the bottle on your back makes it quite awkward.

This solution was the best and very cost effective at around €350-€400