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1. Underwater activities are less varied, the most   of which are snorkelling and scuba diving. Snorkelling involves swimming face down just   the water surface while breathing through a slender plastic tube called a  . Scuba divers, on the other hand, carry a big tank of air that allows them to breathe while deep underwater.
Aquatic sports have   been acknowledged as excellent ways to take physical exercise. Furthermore, practising them is known to produce both psychological and physical   which help to improve mood states and reduce the risk of many serious  .