Donning and Doffing Sidemount tanks

Everything has an order

Keep it consistent and you will never forget anything, plus, you’ll be doing it right each time!
Donning and doffing sidemount tanks, as I was thought and now how I have perfected it, made me want to share with ALL of you this little secret. OK, it has nothing of a secret because it should be taught at Basic Sidemount class but it is not always and for the self taught, well, here is a way to look better at doing it.

Remember, because we are scuba diving in sidemount, everybody watches us – yes, they do! In fact I would say they envy us 😀

In the idea of trying to keep as close as possible from the DIR concept (comments here are welcome), my configuration, the one I teach, comes with the long hose on the right cylinder and the neck-lace shorter hose (with a 90° fixed elbow) comes to the left cylinder. This latter, is called the primary cylinder, as for us, lucky warm water divers, is the one with the LPI wing/BCD inflator.

If you read this and you are not so lucky and dive cold water in a drysuit, you could have the order reversed. For example those diving a certain brand of sidemount harness (interchangeable dump/inflator) will have the dry suit connection off the left tank and the wing off the right one. Does that change the order of primary to secondary? It depends how you see it really. As far as I would go, my dry bag is NOT a buoyancy device but… Another debate for another interesting article. 🙂

So here we are, it is going to come as a succession of photos with explanation and a little summary. Enjoy 🙂

Thanks to my private model for the photo-shoot 🙂 Thanks Richard 🙂


sidemount tanks

First of all, set the tanks to have the right and the left one in the correct position.

left tank first

Left tank first. Get hold of the tank by the first stage, with the right hand and the left hand finds the piston clip and attach the cylinder to the harness.

Bubble check

Once left tank is clipped, it is time to open the valve and do a first self-bubble check. Once done, deploy bungee from around the valve and fully deploy short hose from retaining band. Giving a forward rotation to the turret of the first stage will help keep the hose away when securing the sidemount bungee.

opening tank

Same view but from underwater – switch valve ON prior to deploying hose.

Dry test

After securing the cylinder with the bungee, time to connect your LPI and get some buoyancy. Then, rotating towards the shoulder the turret of the first stage, pass the short hose behind the head and orientate the second stage properly. Bite into the mouth piece then, pull on the necklace bungee around the head/helmet. Time now to test the second stage, face in the water.

Right tank ON

Now that the left tank is on and fully checked, time to do the same but with opposite hand for the right tank. So, left hand gets hold of the first stage while the right hand finds the piston clip and secure the tank to the harness.










right tank open

Just after clipping tank to right hip rear D-ring, while cylinder still submerged, crank open the valve and do your self-bubble check. Then, it is time to secure it with the sidemount bungee.
NOTE: the long hose stays in place until the tank is secured on both attachment points.

Dry breath regulator

Once deployed, the long hose crosses in front of the chest, clockwise and the second stage goes in the mouth to be tested, underwater.



So here we are now, with our tanks (or cylinder, which ever you prefer!) ON and ready to go sidemount scuba diving. It is done the same way for open water diver and/or for sidemount cave and/or technical divers. The long hose needs to always be on top during the ‘exploration’ part of the dive. Once doing deco dives, the deco cylinder, righ or left, takes the ride over the others but it is a good idea to cross the long hose and pass it over. In case of a TOXIC switch, back gas, is always better than the pure O2!!

Long hose deploy

To end this sequence, it is a good habit to get into, is deploy the long hose and switch to necklace to ensure that long hose is free. It is called a ‘modified S-Drill’. So that is ALL I had to say about #DonningDoffingSidemountTanks 🙂 Hope you liked it and see you in the comment section 😉

About Jason

Essential Scuba Training is aimed at divers looking to better their skills in recreational and technical diving while using a holistic configuration. Be it recreational or technical and/or cave diving, Essential Scuba Training will put it's twenty years of experience at your service. View all posts by Jason

6 responses to “Donning and Doffing Sidemount tanks

  • Tyler Phelps

    Nice post Jason! I’m a side mount instructor too. I have a couple nuances to donning. Say I’m going off a boat: before I enter the water, the wing is always orally inflated first. I usually just have the Divemaster or deck hand give me both the cylinders at the same time (that way they don’t have to worry about me and can help other divers). I clip both cylinders on the back D-ring, once attached then I go into my bubble checks and such. But I like how you emphasize the importance of the first stage check and making sure that the hoses are pressurized before donning them!

    • Jason

      Thanks for your message Tyler. I would nuance it a bit more if you allow me. How about just clipping the neck of the tanks, via a shock cord type and leave the bottom free? It also depends what boats and what water entry you adopt.

  • Steve Davis

    Thanks Jason, just the way I do it of course! I have this bedded into muscle memory now so no issue there. I have also bedded in boat entries donning cylinders in the boat and then deco cylinder in water and all cylinders donned/doffed in water. I use cylinder neck clips to chest D rings for this.

    The skill I still need work on is stowing the long hose after full deployment e.g. S-drill. Sounds crazy but that long hose has a mind of its own :). I’ll keep practicing!!!

    • Jason

      Hi Steve, glad you are putting the effort to keep your skills sharp. This also a reason for success: keep training yourself.
      Good water entree techniques too.
      Looking forward to diving with you again soon. 🙂

      Ps: did you manage the tank trim?

  • Steve Davis

    Not yet, being stuck in San Jose is not a recipe for daily diving 😢. Hopefully in the next month or so. I’ll try out your suggestions and let you know.

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