Wearing a scuba cylinder on your back works for most diver most of the time, but it's not always the best option. Some recreational and tec divers use sidemount, which repositions the cylinders along your sides under your arms. Sidemount has several advantages including easy cylinder donning and removal, a lower profile (often useful in activities like cave diving) and less need to wear tanks out of the water. Although it appears awkward, it is one of the most streamlined and comfortable ways to dive.