What is a helmet diving? Helmet diving is the safest and easiest way to visit the undersea. Forget the barred windows and the lead boots! In shallow water helmet diving, you walk and your head is completely dry. You can wear glasses or contacts, as you normally do. Unlike snorkeling, you do not know how to swim. What is a Sea Trek? Sea Trek is a guided underwater walking tour. Air is supplied to a helmet, worn by the Sea Trekker, via a compressor on the surface of the water.