Twin 7's with BC (jacket style) possible?

[lynsey.a]

Hi,

Im looking for some advice please.

I am currently seriously considering purchasing twin 7's (300 bar).


For a few reasons - i will be able to do deeper and longer dives, i feel that it will be more comfortable on my back, less hoses around me (pony regs and pressure gage) and will be safer as i would have a greater air supply in an emergency.

I will be able to do 2 dives off it no problem - my current two tanks are 8ltr 300bar, and 9ltr 203bar with a 1litre pony.

My problems are these -
i dive with a northern diver BC - i have checked and the label in the pocket states that it can have twin 12's on it maximum.
But how would i attach it? The plastic backplate only has slots for a single cam band (rules out the buddy twin bands) and i cant see how SS bands would bolt on to it. The two bolta that are on it bolt the current standard plastick backplate on the inside to a light small one on the outside of the BC.

Would i buy an aluminium (lighter for taking on holiday) backplate and bolt it on instead of the plastic one that is standard? (keeping the plastic plate on the inside of the bc with the aluminium on the outside of the BC instead of the standard plastic one?)

The reasons that i wish to keep my curent BC (instead of purchacing wings) is that i am comfortable in it, i know it well, it fits well, has plenty of lift and i dont wish the expense of buying a new one!

So what do you think? I have carried out google and forum searches about this but i was unable to come up with anything.

Cheers!
Lynsey.

 

[Doc Intrepid]

It is indeed possible to bolt a set of double tanks to a BC. I dove that way for many years in the 1980s. I used a plastic backplate, so it can be done - but I'm unfamiliar with yours, so cannot speak to its suitability.

What you require, primarily, is a set of bands with "bows" - the bows nestle into the curve in the backplate where the single tank would ordinarily fit. You may need to drill out the areas where the bolts must go through the backplate, but essentially the backplate bolts to the "bow" part, and the bands themselves bolt separately to the tanks.

It can be a bit challenging to put it all together if you've never done it before, so working with a mentor or shop owner would be advisable.

I'll see if I can't find some illustrations of bands with bows.

Meanwhile, be advised that its possible that your specific bouyancy compensator may not be suitable. Not all are. (I'm not familiar with yours - its a matter of the size of the backplate and how it is installed into the BC.) In the event that yours is not, despite your familiarity with it you may need to make a choice between a different BC and doubles, or sticking with yours and using singles. You best bet would be to contact the manufacturer and inquire into the required parts.

Regards,

Doc