Proper Sidemount Stage Rigging for Cave Diving
Why Stage Cylinders Behave Differently in Sidemount
Problems with Poor Rigging
Why Trim Changes During Gas Use
Sidemount Stage Cylinder Options
Which Configuration, Top or Bottom, is Better?
Why Stage Cylinders Behave Differently in Sidemount
Most divers use standard AL80s for stage cylinders. They are lightweight and only add 4 pounds/1.8 kg of negative buoyancy. However, they are also very bottom light when the gas inside of them is breathed. The valve and 1st stage regulator add weight to the top of the cylinder, but the bottom doesn’t have the same negative buitancy. Some divers use weights along the cylinder body, but that comes with its own issues.
Problems with Poor Rigging
Rigging stage cylinders properly is the most effective thing you can do to get them to behave properly. Many divers start out using the standard stage cylinder rigging used with backmount configuration. That only results in cylinders that are not streamlined. When positioned below the diver, the stage cylinder hangs too low. When top mounted, the stage cylinders float up and risk damaging the cave ceiling. Stage cylinders must be firmly secured against the torso to minimize movement away from the body and remain streamlined.
Why Trim Changes During Gas Use
Gas has weight. A full AL80 has about 4 pounds/1.8 kg of gas in it. That means that as you breathe from the cylinder, the cylinder becomes more buoyant. While the cylinder may lay flat on the bottom when heavy, if you remove your cylinders in the water, you have probably noticed that it sits vertically at the end of the dive. This is happening throughout the entire dive as you breathe from the cylinder.
Sidemount Stage Cylinder Options
There are two common options for rigging and carrying stage cylinders when sidemount diving – top mounted and bottom mounted. The rigging is similar. The differences lie in the bungees. You can rig a stage cylinder so that it can be used in either position.
Which Configuration, Top or Bottom, is Better?
One method have superior to the other. It’s a matter of personal preference. Top mounted stage cylinders can be a bit more difficult to clip in place. Bottom mounted stage cylinders can feel cluttered when used with steel cylinders. The best option is to try both methods and determine which one fits your diving style best
Where to Learn the Full Rigging Method
The full step-by-step stage rigging configuration is covered in detail in Sidemount Diving The Almost Comprehensive Guide
Readers of this article can receive $10 off the book Sidemount Diving when purchasing directly from the website.
Use code STAGE10 for the Sidemount Diving Guide during checkout.
Related Articles
How to Choose Sidemount Cylinders
How to Properly Manage Gas in Your Cylinders
How to Choose Proper Hose Lengths
Sidemount Cylinder Rigging: What Matters Most
How to Rig Top Mounted Stage Cylinders
How to Rig Bottom Mounted Stage Cylinders
Common Modifications of the Dive Rite Nomad
Return to The Complete Guide to Sidemount Diving Configuration