Snorkelling is swimming while using a snorkel as your only breathing apparatus. The short length of the snorkel means the swimmer has to stay close to the surface. But it means that with a mask or goggles, the snorkeler is able to enjoy the view of the sea without constantly having to take their head out of the water to breathe. Snorkelling is a very popular activity as it allows swimmers to experience the conditions of diving without the burden of heavy equipment. Snorkelling can be an excellent introduction to diving if youêre thinking of taking it up..