Most sports are constantly evolving as new approaches are tried, usually as an alternative to the conventional approach rather than replacing it. Scuba diving is no exception.
Side-mount diving involves mounting a diver’s tanks along his or her sides, below the shoulders, instead of on the back. It is an approach that helps meet some of the challenges in cave diving. For instance, when the cave ceiling is low side-mount tanks give a diver more clearance and also reduce the risk of damaging the tank’s valve on the rocks above. It also simplifies changing tanks. Technical divers are now using side-mounts more frequently.
Side-mount divers may have two or more primary cylinders attached at the side of the body. Bungee cords attached to the cylinder valve help secure the top of the tanks. The bottom is secured to the diver’s lower harness. As a result the tanks are snug against the body to reduce drag. If the diver is only using one tank, a weight can be added to the side opposite the tank to achieve stability.
Side-mounted tanks also enable easy access to regulators and valves, which enables a diver to quickly identify a problem. Another advantage of the smaller side-mount tanks is that they are lighter and easier to carry.
Cave divers in the United Kingdom pioneered side-mount diving 50 years ago. Diving in under-ground water they developed dive gear that would enable them to enter passages that could not be navigated with traditional gear.
American divers in Florida adapted the British equipment during the ‘70s to have better access to caves. The prolonged time in scuba gear led to the development of better buoyancy control and trim.
While early side-mount enthusiasts adapted their own equipment, it is now available to divers off the shelf. Some of it is designed for recreational divers.