Sidemount diving is more comfortable:
Most divers who use sidemount will say it is far more comfortable than diving back mount, especially those who have back problems and find it is difficult to carry heavy scuba cylinders. Usually sidemount set up cylinders will be attached to the harness in the water, so the diver doesn’t need to carry any heavy equipment around on the boat.
Sidemount diving offers more redundancy:
Redundant gas supply has always been an important feature of technical diving, but recreational divers used their buddy’s alternate air source or a pony bottle as an emergency option. Having a second cylinder and regulator means even if one fails, you have a working back up for ascents.
Sidemount is more streamlined:
Wearing the cylinders on your side, tucked under the armpits is far more streamlined than the classic back mounted system. This means less energy is required to propel yourself through the water, which in turn means less air is consumed. Most divers will argue that buoyancy control and good body positioning is easier using sidemount than it is with back mount.
Sidemount diving is more fun:
Ok so this is not such an important benefit, but it doesn’t make it not true. There isn’t much out there that isn’t more fun than un-clipping one or both of the tanks, bringing them in front of you and pretend you are flying like superman! Also divers who continue with their diving education feel more satisfied with the sport as learning new skills keeps things fresh!
Remember the best way to get more out of your diving career is to keep taking on new challenges and never stop learning.