Power snorkel / Snuba on your own?

Dh and I will be in Calica in a few weeks. We have been wanting to try either snuba or power snorkeling. Does anyone know of any independent operators who do these? I could book snuba through the ship, but I like doing independent tours and booking on my own better. Any tips or advise on either whether it was ship booked or not is greatly appreciated.

Anybody?? Cricket...cricket... ;)

Has anybody on here done either of these activities? How did it go?