Sidemount Diving: What It Is and Why Divers Use It

Quick Answer:

Sidemount diving is a scuba configuration in which cylinders are carried alongside the diver rather than mounted on the back. The cylinders are attached to the diver’s harness at the sides and rear, allowing them to be removed, adjusted, or managed independently.

Originally developed by cave divers in the United Kingdom to explore submerged sections of the air-filled caves they were exploring, and later brought to the Florida cave diving world by pioneer underwater cave explorer, Woody Jasper, sidemount diving has grown in popularity because of the flexibility and redundancy it provides. Many divers now use sidemount systems in environments ranging from caves to open water.

Understanding how sidemount equipment works is the first step toward configuring the system effectively.

What is Sidemount Diving?
How Sidemount Equipment Works
Advantages of Sidemount Diving
Challenges of Sidemount Diving
When Divers Use Sidemount

What Is Sidemount Diving?

In traditional backmount scuba diving, cylinders are attached to a harness or buoyancy compensator on the diver’s back. Divers who incorporate a twin cylinder configuration go one step further and mount the heavier cylinders onto a steel, aluminum, or kydex back plate to provide stability. They also add a manifold to the valves so the gas from both cylinders can be breathed from either regulator.

Sidemount diving is a scuba configuration in which cylinders are carried along the diver’s sides rather than mounted on the back. This configuration gives the diver direct access to valves, regulators, and gauges throughout the dive and allows each cylinder to be managed independently. Because the cylinders are positioned along the body rather than behind it, sidemount systems often provide greater flexibility in how equipment is configured.

How Sidemount Equipment Works

A sidemount system typically includes:

a sidemount harness
two independent cylinders
regulators for each cylinder
bungee to control cylinder position

When properly configured, the cylinders are in alignment with the diver’s body, creating a streamlined profile in the water. Several factors influence how cylinders behave in the water, including harness geometry, cylinder rigging, and hose routing.

Advantages of Sidemount Diving

Many divers choose sidemount because of the many advantages it offers.

Redundancy

Each cylinder in a sidemount system is independent, providing a built-in redundancy that many divers find reassuring.

Flexibility

Because cylinders are attached individually, divers can remove or reposition them easily when navigating tight spaces or entering the water.

Streamlined Positioning

When configured properly, sidemount cylinders can align closely with the diver’s body, reducing drag in the water.

Challenges of Sidemount Diving

Although sidemount offers many advantages, it also requires careful configuration. There are a variety of challenges associated with sidemount diving. Harness geometry, cylinder trim, hose lengths, bungee lengths, and gas management are some of the challenges that must be faced and overcome.

Small differences in equipment setup can significantly affect how cylinders behave in the water. Improper configuration may lead to problems such as cylinders floating upward or hanging too low. Achieving a stable and streamlined setup requires attention to details such as cylinder rigging, harness geometry, hose routing, and gas management.

When Divers Use Sidemount

Sidemount diving has its beginnings in cave diving. In the UK, it was mainly used to facilitate the transport of scuba cylinders through dry portions of the caves for use in submerged areas. As sidemount was gaining popularity among UK cave divers, Florida cave diving exploration was reaching its heights. Many exploration dives were ended where restrictions prevented divers with backmounted cylinders to continue. The advantages of sidemounted cylinders were quickly realized and underwater cave exploration took on a new form.

Today, sidemount has gained popularity among recreational open water divers as well. Every training agency has a sidemount course and almost every scuba equipment manufacturer has its own version of a sidemount diving rig. It’s not uncommon to see divers of all levels using sidemounted cylinders rather than backmounted cylinders. Open water divers have even adopted monkey diving (single cylinder sidemount) when diving from boats.

Learning Sidemount Diving

Divers interested in sidemount diving often begin by learning the fundamentals of equipment configuration and gas management.

Proper instruction helps divers understand how the various elements of a sidemount system interact to produce stable trim and efficient equipment management.

Many divers find that learning these principles greatly improves their comfort and confidence in the water.

Final Thoughts

Sidemount diving is more than simply attaching cylinders to the sides of a harness. It is a system in which equipment configuration, trim, gas management, and cylinder positioning all work together. Understanding how these elements interact is essential for building an efficient and streamlined sidemount configuration.

The complete system of sidemount configuration and equipment setup is explained in detail in Sidemount Diving: The Almost Comprehensive Guide.

Readers of this site can receive $10 off the Sidemount Diving book using the coupon code SIDEMOUNT10 and $5 off the Recreational Sidemount Diving book using the coupon code SIDEMOUNT5 when purchasing directly from the website.

How to Trim Out in Sidemount
Sidemount Cylinder Rigging: What Matters Most
Why Your Sidemount Cylinders Are Floating
How to Choose Proper Hose Lengths for Sidemount
Sidemount Gas Management Explained