Sidemount: Principles For Success – Mastering Balance, Streamlining, and Redundancy

In the early 2000s, if you walked onto a dive boat with two tanks strapped to your sides instead of your back, you were considered an outlier—a cave diver who simply hadn't learned how to socialize with "normal" recreational divers. Today, sidemount diving has exploded beyond the sump and the cavern. It dominates technical wrecks, penetrates pristine coral reefs, and is rapidly becoming the configuration of choice for solo divers, photographers, and even warm-water vacationers.

But here is the hard truth: Sidemount is not a short cut; it is a discipline.

Many divers try sidemount once, feel like a barnacle-covered anchor, and declare it "unstable." Others succeed brilliantly, gliding through restrictions with the grace of a fighter jet. The difference between struggle and success is not talent or money. It is adherence to a few immutable principles.

This article deconstructs the sidemount configuration into seven core principles. Whether you are rigging your first set of AL80s or trimming out steel LP85s for a 6-hour cave dive, these laws apply.

Principle #7: The Pre-Dive Ritual – "Sidemount Snake"

The backmount pre-dive check (BWRAF) is insufficient for sidemount. You need the Sidemount Snake—a continuous flow of checks from left to right.

Principle 2: The "V" of the Chest – Harness Geometry is Destiny

Recreational backplate divers love their continuous webbing—one piece, no padding, minimalist. In sidemount, you cannot simply thread the same rigid straps sideways. The human torso is conical, and your shoulder blades move. A poorly fitted sidemount harness will rotate tanks into your armpits, pinch your neck, and cause lower back pain.

The principle here is the "V" of the chest. Your two lower buttplate clips (or hip clips) should attach to a point that allows the cylinders to lie parallel to your torso, not splayed outward like a drunken sailor.

Principle 3: The Leaning "L" – Tank Trim and the Roll-Off

In backmount, the tank is fixed. In sidemount, the tank is a lever. And levers cause rotation.

If you clip a cylinder to your chest D-ring and bottom clip, but the tank's center of buoyancy is behind your center of gravity, you will roll onto your back (feet up, face to the sky). If it is too far forward, you will pitch head-down.

The solution is the Leaning "L" position. When viewed from the side, your tank should angle slightly back—the valve higher than the boot. Typically, a 5 to 15-degree tilt.

Do this for both sides. In current. In low visibility. With dry gloves.

Why most divers fail: They practice this on land, perfectly, and then discover that a current or a ripping surface chop makes the tank wobble. Success requires you to stabilize the tank with your elbow while your hand works the valve.

Pro Tip: Tuck your elbow against your hip to lock the tank in place. Now rotate the valve. If your elbow is floating free, the tank will spin and you will fail.

The "Lost Tank" Scenario

What if a bolt snap fails and your tank drops to trail behind you by the hose?

• Don't try to reach it. You can't. Your shoulder doesn't bend that way.
• Do a helicopter turn to face the trailing tank.
• Reach forward with your opposite hand to grab the valve and re-clip it.

Most divers fail here because they spin in circles. The principle is simple: Turn your body to face the problem.

Conclusion

Sidemount diving offers a unique set of advantages that can enhance your scuba diving experience. By understanding the basics, adhering to key principles, seeking proper training, and engaging with the diving community, you can enjoy the benefits of sidemount diving safely and successfully. Whether you're exploring shipwrecks, navigating through tight spaces, or simply enjoying the underwater world, sidemount diving can open up new possibilities for your underwater adventures.

"Sidemount: Principles For Success" outlines a methodology focusing on streamlining, stability, and redundancy to master sidemount diving, promoting a minimalist approach to gear configuration. The system emphasizes precise equipment setup—specifically harness and cylinder positioning—along with maintaining perfect horizontal trim for improved comfort and safety in both recreational and technical diving. For further reading, see the Facebook group discussion on Sidemount: Principles for Success Sidemount: Principles For Success (eBook) Feb 5, 2569 BE —

"Sidemount: Principles for Success" by Andy Davis is a 251-page guide focusing on the technical, philosophical, and gear-optimization shifts required for proficient sidemount diving. The resource emphasizes accessibility, streamlining, and mastering foundational skills in open water before attempting advanced environments. The ebook is available for $25, with details on Scuba Tech Philippines and the author's Buy Me a Coffee page.