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Stealth 2.0 Single Sidemount Diving

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Stealth 2.0 Single Sidemount Diving

Stealth 2.0 Single Sidemount Diving

Stealth 2.0 Single Sidemount Diving

The Stealth is the perfect harness for technical sidemount diving and you can also benefit when diving with a single tank.  This is great if you want to switch between technical and recreational diving ‘modes’ on holidays, and the change only takes as long as it does to swap a regulator – sidemount for all occasions!

Weight and balance

The first question most people ask about single-tank sidemount is “aren’t you unbalanced?”  It may look that way but when set up correctly it certainly doesn’t feel that way.  You just need to consider the buoyancy characteristics of the cylinder and how it effects balance.

If diving with a standard aluminium cylinder, which becomes ‘positively buoyant’ late in the dive, you may not need to adjust any weights at all.  Actually, aluminium cylinders combined with a first stage regulator are usually just negative at the end of a dive, and for many people the weight difference is not significant.  However, a 2lb (1kg) counterweight (on the opposite side of your body from the cylinder) can improve balance earlier in the dive.   Either a trim weight in a pocket or a threaded weight will work.  Any heavy accessories (e.g. a large torch) may also work as a counterweight when located on your opposite side from the cylinder.

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If you’re a photographer and spend time stationary (and not on the bottom) the effect of the cylinder’s weight on your balance will be more noticeable and you may want a moveable counterweight.  When the cylinder is on the left side the counterweight starts on the right side and is relocated closer to the centre later in the dive.  A 2lb (1kg) weight in a moveable trim pocket or simply bungeed onto the Stealth’s waistband can work well enough.

Importantly, counterweights are not additional weight, they are your existing weights repositioned – there is no benefit to over-weighting.

With steel cylinders there is no choice but to use a counterweight.  The amount of weight depends on the cylinder and where the counterweight is located; the further to the right (e.g. on the hip) then less lead may be needed.  For example, a typical 10.5 litre 232 bar steel cylinder can be balanced by about 6lbs (3kg) of counterweight in a trim pocket sitting low on the Stealth’s shoulder strap.  We (my wife does this too) have found this to be a good place for the trim pocket because we don’t need to reconfigure anything when changing between single and twin cylinders – the trim pocket just stays there.  We use ingot style rectangular weights and we can just squeeze 6lbs (3kg) into the small xDeep trim pockets (note: the trim pockets are not ‘specified’ for this weight but they are so well made that we have never had a problem); however, the larger trim pocket would probably be more suitable.

Before diving single-sidemount with a steel cylinder, we recommend that you find out more about its buoyancy characteristics.  A good place to look is the manufacturer’s website, which often list full and empty buoyancy characteristics.  Allow a bit more negative buoyancy for the first stage regulator and decide on the counterweight you need.  Then go for a dive or three - any excuse for a dive is a good one!

Single Sidemount Regulators and Cylinders

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First stage regulators with a swivel turret are great for twin cylinders.  Changing to a single cylinder simply means adding another second stage regulator to the left side first stage (ie, the one with the BCD inflator hose).  However, divers new to sidemount may want to use their existing, recreational regulators.  There are many different regulators available, but in this case I’ll refer to the Apeks XTX200 – regulators that I’ve dived with for a few years with both backmount twins and singles.

The first stage has four LP ports, two on each side in roughly parallel positions.  For a standard back-mount single configuration, one change is essential.  With the cylinder on the left of the body and a standard right-feed regulator hose passing behind the neck, a standard regulator hose is too short.  There are two simple options to fix this (and not have the hose looped in front of your face).  First is to use the alternate air source on its longer hose if the ease of breathing is similar to your primary regulator, but this leaves the primary regulator on a shorter hose if you need to share air.  I prefer a second option, which is to fit a 90 degree swivel to the primary second stage regulator, the same as I use on the left regulator for regular sidemount (Karen, my wife, prefers a 360 degree swivel).

Using cylinder valves with an extension post (opposite side from the hand wheel / valve knob) is ideal with a loop bungee as the bungee rotates and pulls the cylinder into the diver’s side.  For cylinder valves without an extension post the bungee may have to loop under the valve and connect to a D-ring with a bolt snap.  For this method the bungee does not pull the same way, and the lower cylinder bolt snap should be repositioned in-line with the valve opening.  Of course, you could have the cylinder valve face away from you and loop the bungee around the hand wheel – many options are possible.

When positioning the regulator on the cylinder valve, and using standard length hoses, I prefer to rotate the first stage so that the both regulator hoses point up and the inflator hose, dry suit hose (when using a dry suit) and SPG hose point down the cylinder.   The inflator and dry suit hoses are held under hose retaining bands (or bungee again!) and are turned in towards the diver’s body.  From there they can be pulled out and connected onto the BCD inflator and dry suit QR posts.  The dry suit hose is usually longer than the BCD inflator hose, but for the Stealth I swap these around because the BCD inflator needs the longer hose.

The regulator and SPG hoses are held on the cylinder and looped away from the inflator hoses.  The first hose being the SPG hose which I loop down and back up so that the SPG is in an easy to read position.  Next the alternate air source hose, initially pointing up from the cylinder, is looped down the side of the cylinder, under the retaining bands, and back up so that the second stage regulator rests near the top of the cylinder.  In this position the SPG is easy to read and the alternate air source is easy to donate if needed.  The hose for the primary regulator is usually too short to loop under the retaining bands, so I wrap a bungee necklace around the first stage regulator to keep it neat when carrying the cylinder. Now it’s ready to be put on whether you are in a boat, on shore, or already in the water. 

Dave

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