Appeared in DIVER October 2007

John John Bantin has been a full-time professional diving writer and underwater photographer since 1990. He makes around 300 dives each year testing diving equipment.


Have you got a drysuit How do you dump air from that Why do you need a corrugated hose on your BC Because the first ones made had no direct feed and they were filled by mouth (yes, under water!).
Todays BCs almost all have a dump valve, operated by pulling on a cord and toggle or on a wire that runs inside the corrugated hose. There is never any reason to lift the corrugated hose to dump air, thereby filling the BC with the water that comes back in the other way.
Mares was at the forefront when it came to doing away with that silly hose, but instead of using a mechanical system with wires, it harnessed the pneumatic power of the compressed air in the divers tank.
I once had a car that used hydraulics for major functions. The doom brigade suggested that a non-mechanical system would be fraught with complexity, and unreliable. I pointed out that airliners used hydraulics - fly-by wire is not simply a Bowden cable connection!

The Origin Sport is a fairly basic and conventional BC, so if its your size, it feels quite comfortable. It has a wide cummerbund with a strap over, and a sternum strap to keep the shoulder straps from pushing apart. I usually use such a strap for tucking away the corrugated hose, but its not needed in this case.
The integrated-weight system has pouches that locate nicely and clip away securely. Its been some years since I watched my integrated-weight pouches spiralling away below me, now that most manufacturers have improved their systems.
The integrated-weight pouches stowed without fuss. They look as if they would easily take 5kg each side but without that feeling under water of riding a bike with two bags of shopping on the handlebars. I used only 3kg.
The weights system truly integrates with the diver. Alas, there are no trim-weight pockets. They would have come in useful if diving with a large aluminium tank, but as it is you would have to stash weights using the camband on the tank.
The BC proved easy to put on without getting into a tangle.

Under water, there were no nasty surprises, though the Origin Sport does have a couple of fairly useless zipped pockets.
I thought I would find them convenient for stowing a current hook and a back-up light, but placing any lead in the integrated-weight system leaves hardly any space.
At least the zips run in a direction that allows you to feel for them.
There is only a single D-ring at the shoulder, and two at the lower front edge. Thats enough for most of us, but my octopus rig would have dangled less awkwardly had it been attached to a D-ring positioned higher on my body.

Control of Buoyancy
The Mares AirTrim system uses two oversized controls positioned so that they fall easily to hand once you have distinguished the upper one from the left-hand integrated-weight pouch release.
The upper button opens the air-inlet valve, supplied with air via a direct-feed hose.
The lower button is used to open two dump-valves simultaneously, one at the shoulder and one at the lower back.
This way the air escapes no matter what your angle is in the water. Job done.
Ah, but what if your tank is empty Will you be able to dump expanding air as you make a safely slow ascent Well, there is an alternative manual dump-valve operated by the usual cord and toggle, at the upper right shoulder.
In fact I often used this routinely during an ascent, simply because I was used to it and didnt have to stop to decide which of the two AirTrim buttons I should have been pressing.
Overall the AirTrim system works like a dream, albeit the noisy sort of dream enjoyed by a man who snores a lot.
The buttons are big enough not to miss once youre used to them, and thats by feel alone. Air went in on the way down and out on the way up, which is how I like it.
The blue direct-feed hose seen in the photographs is a non-standard Miflex Xtreme braided hose rather than the conventional one supplied.

Surface Support
Lets assume you are at the surface and need to inflate but your tank is finally empty (we all make mistakes!). You simply haul out an oral inflation tube from inside a pocket.
And if youre not at the surface
Well, a corrugated hose would be no more useful!
Designed for use with a single tank, this BC does not provide a high maximum lift. Surface support proved adequate rather than startling, and I cant see the Origin Sport being readily adopted by diving instructors for their students.
On the other hand, there is enough lift for any experienced diver who doesnt mind getting his head wet from the occasional big wave while waiting at the surface.
I used it with a 15-litre steel tank and 6kg of lead and had no complaints.

Ease of Removal
When the time comes - and not before - the weight-pouches pull away in a flash. The big toggles provide something meaty to get hold of, even when wearing gloves.
The shoulders unclip easily too, and the BC proved very slick to swim out of once it was fully inflated.
The weight-pouches are readily reinstalled as well, although I would suggest that you do it yourself rather than leave it up to a helpful crew-member, however inconvenient.

Air Trim control and weight release
oral inflation tube
AirTrim dump valve

STYLE Conventional
POCKETS 2 zipped
DIVER GUIDE width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100%