It was summer 2012,and British school teacher Polly Shoebridge was nervous as she prepared to scuba dive for the first time.She was in the water in full dive equipment,building up courage to descend off the coast of Cancún,Mexico.“Initially,I focused on breathing,”she recalls.“Then as I went down,I started to relax. It was summer 2012, and British school teacher Polly Shoebridge was nervous as she prepared to scuba dive for the first time. The was was in the water in full dive equipment, building up courage to descend off the coast of Cancún, Mexico. ”Initially , I focused on breathing, “she recalls. ” Then as I went down, I started to relax.