The AirTrim ‘console’ on my Mares Vector

It’s a given whenever I dive with a new group of people that, at some point in the trip, someone will ask me about my BCD. I’ve always been the only one on the boat with an AirTrim system, and it seems most people have never even heard of them, let alone seen them, so it seems like a good idea to share my experiences.

First, a basic introduction to the AirTrim system. It basically provides an alternative way of inflating and deflating your BCD. Instead of the ‘traditional’ pair of hoses that hang over your left shoulder, AirTrim has a two button ‘console’ of sorts fixed to the left side of the BCD, about where the hoses would hang (see photo). The console is large and easy to find without having to look down. It may seem a little flimsy, and I was warned by the sales guy that this was a possible weakness, but in the heavy use I’ve given it for over two years it has proved quite tough.

One of the console buttons fills the BCD with air from the low pressure inflater hose, which attaches as normal. The second button operates an actuator that opens a dump valve on your left shoulder, about where the traditional type of BCD hose would attach. The actuators operate using the air pressure from the inflater hose. The Vector model that I have also has a actuator operated dump valve near the bottom seam, near your right butt cheek. This combination means you can dump air even when you’re in a head down position.

This, of course, is the main selling point of the AirTrim system, and why I bought the Vector. I purchased the BCD very soon after I got certified, and if I had it all to do over again, I would hold off buying a BCD until I had more experience. I had several frustrating encounters with rentals that made me think I really needed to get my own BCD. The AirTrim system appealed since I knew I wanted to get into underwater photography.

AirTrim doesn’t allow you to dump air from any angle, but it does make it much easier, especially with the lower dump valve. If I’m trying to photograph something and need to reduce my buoyancy more than I can accomplish with the air in my lungs, it’s quite simple to dump some air with a minimum of repositioning.

The AirTrim valves releases air rather slowly, which most of the time is a good thing. In places like Komodo, where you need to get down quickly, I tend to use the manual dump valve to release air a lot faster.

Would I buy another AirTrim BCD if I were getting a new one? The simple answer is “yes”. I’m happy with the AirTrim system, but I’d look at other factors when buying a new BCD, and they might outweigh the attraction – as well as added cost – of AirTrim. One thing I don’t like about the Vector is that it’s a little too short on me. It’s not that the BCD itself is too small, in fact it’s a little too loose around the waist at depth. I think the short waist was an intentional design ‘feature’ to put the pockets, weights, etc. close to your center of gravity, and for me that puts the pockets too far up to access comfortably. If I were looking for a new BCD, I’d also like something less bulky. In spite of the issues Dive Rite has had recently, I still think their TravelPac looks like a great rig for a diver that has to get most places by plane.

I’ve had my Inon strobe about a year now, and one of my dive partners – also a travel writer – suggested I review it. First, a little about the rest of my setup, and why I needed an external flash: My camera is a Canon Powershot G10. I bought the G10 primarily for diving, based on the advice of several other divers who had earlier versions of the G-series. I saw the results they got and decided this was the right camera for me. I purchased the Canon waterproof housing when I bought the camera. As something of a side-note, the G10 has proved so good that I now rarely bring my older DSLR with me on my travels.

The Inon S-2000 strobe with the Canon waterproof housing, t-bar, grip, etc. Not shown: the diffuser for the flash.

Now, although the G10 takes great pictures underwater, with a pretty good built-in color correction, there’s a bit of a problem when it comes to macro photos. One of the features of the G10 is it’s optical zoom, which gives you the equivalent of a 28 to 140 mm lens. That kind of zoom range requires a lens which can extend out from the camera up to a couple of inches. Of course, the housing has to allow for the lens to extend its full range, so it’s fairly bulky. The result is that the housing effectively blocks the light from the built-in flash on the camera body. Even with the diffuser provided with the housing, you will likely only get light on a quarter of the subject. You can work with it, but it’s far from ideal.

So, I went in search of an external flash. Here in Bangkok, my options were limited. After a little research I settled on the Inon S-2000, a small strobe made in Japan. The unit is relatively compact, and fires optically. It takes four AA batteries, and I’ve recently tried using rechargeable batteries with good results.

The S-2000 has switches on it to allow you to adjust the timing of the flash. It took only a couple of experimental shots to fine-tune the timing with my camera. Actually, I should have spent more time testing the setup before I took it diving, since it turned out that with both the internal and external flashes going, the photographs were over-exposed.

After briefly considering the purchase of the fiber-optic slave cable, I hit on an amazingly simple solution that worked out very well. What I did was take a small piece of dryer tape and stuck it inside the housing over the area in front of the built-in flash. Just to be clear, dryer tape is not the same as duct tape. Dryer tape is thinner and has mirrored backing, which is part of the trick. The tape is opaque, so no light gets through it, but the mirroring ensures that enough light escapes to the side to set off the S-2000. The tape was very easy to fit just right because the housing has fins on the inside to help ‘funnel’ the light from the flash.

I’ve been really happy with the S-2000, and once I got everything synced up, I started getting some great shots, especially macros. The setup really proved its usefulness in Lembeh, where you can see from just the highlight photos how well the gear performs. It doesn’t help much on wider shots, but there’s probably nothing short of a fish-eye lens and two strobes that will help improve that kind of shot.

One thing you’ll want to watch with the strobe is that, if diving in the tropics, as I do, the optical trigger is so sensitive that it can easily be repeatedly set off by sunlight bouncing off the waves when you’re on the surface. To save the batteries, and my eyes, I try to remember to switch off the flash unit before I surface.