Max Gilbert PADI IDC Staff Instructor

Side Mount Diving

Unless someone makes me, I will not dive with a tank on my back ever again.  I’ve been diving side mount for almost a year now, both for recreational and technical diving and I am hooked!  Cave divers and tech divers have been side-mounting tanks, and making homemade side mount gear for years, but the techniques they use are going main-stream.  For them, it was a matter of being able to get through tight restrictions.  For the rest of us, it’s just plain cool and easy.

Quite simply, side mount divers don’t wear tanks of any kind on their backs.  In its simplest form, diving side mount involves carrying two tanks, one under each arm.  The tanks are tied off to a “butt plate” that covers the diver’s posterior, and at the cylinders necks, they are held in place by bungees.   The bungees hold the tanks nice and snug to the diver’s ribs so that overall, the diver and his tanks make a nice streamlined package in the water.  Side Mount Divers also use “safety straps” on the tank’s necks to hold the weight of the tanks should he want to stand up while wearing them.

Diving side mount offers several advantages over traditional back-mounted systems.

1)      No more heavy tanks on your back!  If you have back or other joint issues, take your tanks to the water’s edge with a hand truck, or have the boat crew hand them to you in the water.  Clip them on, slip the bungee in place and off you go!  This advantage is especially nice for technical divers who no longer have to walk hunched over with 100+ pounds of steel doubles.  However, just about everybody finds it easier to carry tanks around by the valves than walking around with them on their backs!

2)      Fully redundant air supply.  You have two tanks, each of which is equipped with a regulator and a pressure gauge.  If one fails, just switch to the working one and make a normal ascent.  If your buddy needs air, hand him a hose and make a safe ascent.

3)      Your regulators and valves are right where you can see them.  You don’t have to wonder if you have a leak because you can just glance down and see what that reg is doing.

4)      Less entanglement risk.  That tank valve behind a back mounted diver’s head just loves to catch on stuff, especially when you’re diving near a wreck.  With your valves in front of you, they’re less likely to get caught on something, and easier to disengage if they do.

5)      Safer.  If you don’t have to carry a heavy tank, have a redundant air supply, and your regs are right under your nose, you have to be safer, right?  Of course, right!

6)      Better streamlining.  When you dive side mount, the tanks don’t protrude from your sides much further than the width of your shoulders.  You’re thinner from back to front, offering less resistance to moving in the water.   

7)      Better trim control.  That back-mounted tank tends to roll divers over onto their backs when they hover, or force us to hover vertically.  Side-mounted tanks are right in line with the diver’s center of gravity, so you can easily maintain a nice horizontal, face down position. 

8)      Better air consumption.  If you are more streamlined, and in a better position in the water, your air consumption rate has to improve, right?  You’d better believe it!

9)      Availability of rental tanks is easier for tech divers.  You don’t have to worry if doubles are available for rent at your favorite Caribbean dive spot.  Grab a couple of aluminum 80’s and hit the water!

10)   Another advantage to tech divers is that they don’t have to travel with a back plate.  In these days of excess baggage fees gone wild, leaving six pounds of stainless steel at home could save some serious money.

The only disadvantages to side mount diving are that you’ll need two regulators, each with an SPG.  One second stage is on a 7-foot hose.  This reg is the one you hand off to an out of air diver - you don’t use an octo in side-mount diving.  The other second stage is on a 40 inch hose, and is worn on a bungee around the neck.   Since you have two regulators, a console computer doesn’t make much sense anymore.  Use a wrist-mounted computer, or put it on a retractor.  Finally, since the tanks are completely independent, redundant air supplies, keeping them balanced is up to you.  Every three to five hundred PSI, switch regulators, so that you keep about the same amount of air in each tank.  After years of diving, I have a pretty good internal timer that tells me when to check my pressure gauge.  I just let it tell me when to switch regulators now.

Sidemount BC’s typically have a butt plate for clipping off the tanks, and specially shaped bladders to give lift near the diver’s hips.  Most manufacturers also realized that not everyone would want to run out and get a new BC, so they have add-ons that will convert a harness BC, such as a Dive Rite Trans Pac into a side mount BC.  Just add the butt plate and bungees, and you’re diving side mount!  In fact, my side mount class had two instructors, and the second instructor, Jacob, used just the arrangement I’ve described.  The tanks were stowed perfectly, his trim was 100% horizontal… he was one squared away diver!

You know me… when it comes to dive gear, I just can’t get enough.  I can’t wait to get in the water and go cruising around.  Ask me nice and you can dive one of my side mount rigs to see if it’s for you.  I’ll bet you love it as much as I do.

Like any new diving skill, you need training and practice to learn and master it.  Southeastern Divers will be offering classes in Side Mount diving starting in June.  Come give it a try!

See you soon ~ underwater… diving Side Mount!

max