Incorporate bilateral breathing into your swim workout. Breathing only on one side will develop the muscles on that side more than the other. This can eventually lead to shoulder problems. By breathing on both sides with every workout you can prevent this from happening.
And remember when swimming outdoors, never dive head first into water unless the depth is known. And, when swimming in lakes or oceans be aware of any natural hazards such as tides and rapids, and never swim alone.
BC physiotherapists are the most physically active healthcare professionals in Canada and the ones physicians recommend most.