Scuba diving with a sidemount configuration simply means that you carry your tanks at your sides instead of on your back. This can reduce drag and is more comfortable for many divers. Sidemount divers often dive with two smaller tanks that are attached in the water. This makes carrying tanks and kitting up easier, especially for those who have difficulty lifting or walking with a backmounted tank. Technical divers typically need to carry extra cylinders, and believe that using a sidemount setup is the best option.