What Is Side Mount Diving?:
• Single Tank Side Mount Diving: A diver carries one tank, usually on his left side. This is primarily a form of recreational diving.
• Double Tank Side Mount Diving: A diver carries two tanks, one on his left side and one on his right side. Double tank side mount diving is used both in recreational and technical diving.
• Stage Side Mount Diving: A diver carries two tanks on either side of his body as well as additional tanks (stages) to extend his bottom time and/or carry different mixtures of breathing gases for deep diving. These stage tanks are attached either above or below the side mount tanks.
Why Dive Side Mount?:
1. Comfort: Many divers find that a backmounted tank interferes with their ability to look up or forward. A smaller diver may find that the tank valve and regulator on a backmounted tank has the tendency to push uncomfortably on his head or neck. Sidemount diving solves this problem.
2. Compact, Light-Weight Systems: Airline luggage restrictions are becoming increasingly stringent. Many divers have difficulty packing an full set of scuba gear without exceeding airline restrictions on luggage weight or number of bags. Sidemount systems tend to occupy less space in a diver's luggage (and weigh less) than backmount systems.
3. Ability to Don/Remove a Tank in the Water: Most sidemount systems do allow divers to back-role or giant stride off a dive boat, just as a diver would do using a traditional BC. However, sidemount systems offer an additional option: a diver can enter the water wearing his harness/buoyancy compensator, weights, fins, and mask, and then clip the tank onto his harness in the water. Divers who cannot carry the weight of a tank for physical reasons may find this an advantage over backmount diving, which requires that a diver either enter the water completely geared up or enter the water without a buoyancy device, and then don the BC and weights in the water.
4. Access to the Regulator First Stage: A sidemount diver can see and access his regulator first stage, unlike a backmount diver. This allows him to visually diagnose (and sometimes solve) leaks or other problems underwater.
5. Access to the Tank Valve: A sidemount diver can both see and easily turn his tank valve. In some emergency scenarios this is an advantage, such as when managing a free-flowing regulator. In the completely avoidable event that a diver enters the water with his tank valve closed, he can easily access the valve and open it himself.
6. Streamlining: A properly configured sidemount system will place the scuba tank in-line with the diver's body, with the tank valve tucked under his armpit. This reduces a diver's vertical profile and drag as he moves through the water.
7. Protected Tank Valves and Regulators: Most sidemount systems place a diver's tank valve and regulator in a more protected position than backmount BCs. A diver using a sidemount configuration reduces the chances of damaging his tank valve and regulator because he can see where they are and because they are protected by his arm.
8. Sidemount Allows Access to Tighter Places: I hesitatingly place this in the "advantages section." For cave and wreck divers who have completed technical sidemount training beyond their initial cave or wreck certification, a sidemount configuration may allow them access to spaces that would be impossible to enter with a backmounted tank. For recreational divers, however, this is almost a disadvantage because it gives unqualified divers the ability to enter tight spaces beyond their certification level. Never enter a wreck, cave, or other closed environment without proper training.
Side Mount Scuba Diving Requires Special Training:
Divers must take a course to learn to use a back mount style buoyancy compensator (BC) properly (usually the water course), and the same is true of a side mount configuration. Of course, a diver who is interested in using a side mount configuration from the beginning of his scuba career may take his open water certification course in side mount and eliminate this step. When a diver is using a side mount equipment configuration, both he and his dive buddy must be familiar with emergency management using the sidemount system. Here are some of the ways in which side mount diving differs from back mount diving.
1. Side mount diving uses a different hose configuration, and therefore a different air-sharing procedure.
2. When using a side mount equipment configuration, accessories must be mounted in a way that does not interfere with the tank position.
3. Entry and exit procedures in sidemount diving differ from those in back mount diving.
4. Side mount diving has additional risks which must be understood and managed, including the risk of a tank roll-off from arm movement.
5. While a side mount equipment configuration offers a diver the ability to manage problems such as a free-flowing regulator underwater, learning to manage them properly requires additional training.
6. When double tank sidemount diving, a diver must "balance" his tanks by switching regulators periodically to ensure that the tank pressures remain within a few hundred psi of each other.
Choosing a Side Mount System:
A wide variety of side mount diving systems are available. When choosing a side mount system, a diver should consider the following:
1. Simplicity: A good side mount system has the advantage that it is more streamlined, and, in many ways, simpler to use and carry than a backmount system. Avoid side mount systems that involve excessive bungees and straps, or that require extreme modifications or accessories to use properly. Simpler is better.
2. Control of the tank: A good side mount system will hold a tank tightly to a diver's body, tucking the tank valve under his armpit. Any system that allows a tank to dangle or sway will be uncomfortable.
3. Size and weight: Good side mount systems typically weigh less and can be packed into smaller spaces than back mount systems. A side mount system that is very heavy or takes up an excessive amount of space is probably not very streamlined or simple.
4. Lift: Be sure to choose a side mount system that provides adequate lift for your dives. Most divers need very little lift when properly weighted unless they plan on carrying more than two tanks.
5. Ability to vent air from different positions: A good side mount system should be able to vent air when a diver is in a vertical position and when he is in a horizontal position.
6. Weight system: Some side mount systems offer integrated weight systems. I much prefer systems with integrated weights to those that require a dive to use a weight belt or place weights on the tanks.
The Take-Home Message About Side Mount Diving:
Learn More About Side Mount Diving:
Check Out the Razor Side Mount System | The Author's Side Mount Instructor Page