the switching, the "which hose to donate" problem, and the need for a difference BC are three that come to mind that dont exist in doubles diving.
Are you actually trained/experienced with sidemount.... or just guessing?
Switching - a relatively simple skill, taught on the appropriate course. Certainly a lot easier to master than shut-down drills 'behind the head'. Divers using indie backmount have been cylinder balancing for decades. The only abilities required are: (1) Regulator remove and replace - an OW skill.... and (2) Situational Awareness of your gas contents - another OW skill.
Which hose to donate - the 'long hose', same as on back-mounted doubles.
The need for a different BCD - There are conversion adaptors that allow regular BP&W to be used for sidemount. If the diver is buying equipment for a transition into doubles anyway, then the cost of sidemount kit is substantially lower. Sidemount kits are available in configuration that match either 'hogarthian' or 'comfort/BCD style' harnesses, allowing easy transition of familiarity from existing kit into sidemount.
PADI released the recreational sidemount course recently - it covers all skills and drills needed to effectively dive with double tanks, but unlike back-mount, is applicable for divers with a much lower experience threshold.... it's even available as an AOW 'adventure dive' elective now. Prerequisite qualification for training is Open Water diver - just how 'complex' are you imagining that it is?!?
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Its not my reason, but I have noticed that going back and forth between sidemounted tanks to keep them equal does take alot of thought.
I'd use the term 'gas awareness'.... and it's something that any technical diver should possess. If a technical diver balked at the concept of having to balance two tanks, then they probably shouldn't be technical diving in the first instance.
Sidemount can (and is) taught to Open Water level divers. It's a new skill set, nothing more, nothing less... and one that's very easy to achieve.
Also, it seems to me that the manifold is an improvement over independent doubles, because it give more alternatives to accessing gas in the event of a failure. No?
Manifold - allows you to create true redundancy, in the event of otherwise catastrophic gas loss.
No-Manifold - provides you with true redundancy, in the event of otherwise catastrophic gas loss.
Gas Planning and Management - provides you with safety factors to account for regulator failure, regardless of configuration. How many 'options' do you need - you either have sufficient gas, or you do not. What matters if you 'lose' one tank, when the other has sufficient to get you back to the surface?
Access to gas through a 'failed' regulator - Sidemount provides access to tank valves, that is either impossible or severely difficult in back-mount. Most, if not all, regulator failures will result in free-flow. With back-mount, that means a shut-down... and reliance on the back-up regulator. Sidemount divers at tec level are taught to 'feather' a free-flowing regulator to access that gas, on demand. Access to gas is not lost, neither is access to the regulator. The diver can still share air, if required. In the worst case scenario, they can even swap regulators between tanks - something implausible for a back-mounted diver - again, this skill is taught on some sidemount courses. For recreational sidemount divers that is all hypothetical, as they'll have ample gas remaining for a direct ascent to the surface. Procedures may be different - but capability and safety remain equal.
You didn't read my blog article yet, did you?
