diamond blade for tiles you can get in format for regular angle grinder. Circular diamond blade costs somewhere around 10-15 bucks. There is diamond dust on edges of blade. Using angle grinder with batter attachment you can grind or cut for hours.
It certainly is possible, I only hesitation is that creating so many entry points for disease or parasites is not a good idea when working in the sea. In lab situations we can test with antibiotics or revive solution, and are working in much cleaner environments. This is a bit like coral surgery :)