Whenever you ask a sidemount diver what they enjoy most about sidemount, they will always mention freedom. It feels similar to freediving. Oneness with the water and being able to move through it freely in any direction. It is the feeling of freedom and weightlessness that has made sidemount diving so popular among divers.
As well as the ability to navigate narrow restrictions, sidemount is also a good choice when diving in caves, mines, and sumps. Nevertheless, sidemount diving offers several fundamental advantages that make it an excellent choice for divers who would like to transition to multi-cylinder, open circuit diving.
The following are my top seven reasons for diving sidemount.
STREAMLINING IS THE FIRST REASON
How many times have you marvelled at the motion of a Dolphin, Seal or Shark? They seem to move with ease. Over the course of many millions of years, they have developed the speed and manoeuvrability necessary for success as marine predators. Increasing speed requires an increase in propulsion power many times greater than an increase in speed due to water’s density of 800 times that of air. Streamlining is important to reducing drag in order to efficiently move through water.
RATIONALE 2 – TRIM
Divers are generally referred to as being in trim if they are facing forward towards the surface. An efficient way to move through the water requires a good horizontal trim. An effective trim depends on the placement of your weight, the weight of your BCD and the positioning of gas in your dry suit. Correct horizontal trim is a hallmark of a competent sidemount diver, though good vertical trim can also be achieved when diving backmount. This is mostly due to the pro-trim effect of having your cylinders on the sides of your body, allowing them to be more closely aligned with your centres of gravity and buoyancy.
BALANCE – 3rd reason
If you mount your cylinders sideways, they will be on either side of your torso. It does not matter how you position yourself, your centres of gravity and buoyancy are always close to the centre of your body. Whether you’re upright or upside down, you are balanced whether you’re inverted or upright.
Backmount, on the other hand, is the mounting of your cylinders on your back.
You will create a significant moment or force when you turn to your side, causing you to back down. Although it can be controlled with body tension, it can be disconcerting and it certainly interferes with feeling balanced while diving in any direction.
Decompression stop of a sidemount diver
STABILITY – 4th reason
The control of trim, balance, and buoyancy is essential for stability. Stability means being almost completely relaxed and staying in trim and balanced. You are in trim when your buoyancy completely balances your force of gravity. In addition to being weightless, you are now a stable platform and can complete tasks or skills while remaining in the water column. When diving overhead environments, such as caves or wrecks, where silt caused by contact with the cave or wreck floor can reduce visibility, it is important to keep this in mind. Decompression diving also requires the ability to perform tasks such as gas switches while maintaining specific depths.
REDUNDANCY – 5th Reason
As well as being able to carry more gas, redundancy is another important reason to dive with two or more cylinders. If an equipment failure occurs or if a diver makes a mistake, redundancy provides additional safety. The cylinders and regulators of multi-cylinder configurations are both redundant. As opposed to an isolation valve, side mounting provides two independent gas supplies. While this aspect has pros and cons, it is a distinctive feature.