How to Buy a BC

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HOW TO BUY A BC

"As I drifted down-current from the boat, I wished my BC was providing better floatation and wasn’t riding up around my nose . . ."

A buoyancy compensator can be your best friend or your worst enemy. It can make a dive easy and enjoyable or a chore. Choosing the right one requires a little planning and thinking.

REAR INFLATION vs. WRAP-AROUND - It used to be that your only choice was a horsecollar. But the stabilizing jacket revolutionized BC design. (Although you can still find horsecollar BCs, most are designed for snorkeling.) Your first decision is whether you want a wrap-around or rear inflation design.

With the wrap-around, the air cell encircles your body and concentrates the biggest volume of air around your hips, which means you ride slighter higher out of the water. But wrap-arounds can feel a bit more restrictive.

Rear-inflation BCs put the entire air cell behind you. They offer more freedom of arm movement and are good choices for photographers. However, because ALL the inflation is behind you, they may tip you forward (which can be counteracted with the addition of a tank weight).

WEIGHT INTEGRATED OR NOT - Divers hate wearing weight belts. (Thus the proliferation of weight-integrated BCs.) But if you dive in cooler waters where you need a full wetsuit, you can get a hernia trying to lift them up. If you go this route, look for a weight-integrated BC with easily removable weight pockets. Put the BC on without the weights, then add the pockets. When you come out of the water, reverse the procedure.

LIFT - You’re not trying to float a battleship. Bigger is not always better. And it’s not to hard to calculate the amount of lift you need. Just add 5-10 pounds to the amount of weight you normally wear. If you wear 20 pounds (like a typical cold-water diver), a BC with 25-30 pounds of lift should suffice. In warm water, where you might wear as little as 10 pounds (or less), a BC with 15-20 pounds of lift will do the job. If you’ll use the BC for both cold and warm water diving, go with the greater lift.

EXHAUST VALVES - "I need more weight!" It’s the battle cry of the chronically over-inflated. "Dump all the air out of your BC!" It’s the response given most often. Being able to easily vent the air from your BC is extremely important.

Let’s start with the rapid exhaust valve on the inflator hose. This should sit high on your shoulder. A wire runs inside the hose. When you pull down on the inflator (at the bottom), it opens the valve at the top, allowing the air to escape.

But this doesn’t work if you’re descending. Since your shoulders are lower than your hips, the air in the BC won’t come out the shoulder dump. So a rear exhaust is invaluable. Just reach back and grab the rear valve (which will now be the highest part of the BC) and vent off any remaining air.

POCKETS - Make sure you can get to them easily. If you normally wear a wetsuit, access the pocket with your wetsuit jacket on. The angle of a zippered pocket will make a big difference in how easy it is to open and close. Velcro opens easier, but is not as secure.

MATERIAL DURABILITY - Ask about the thread count of the material for the BC. The higher the count, the more dense the material, and the longer it should last. A cave diver scraping against walls needs a more durable BC than someone who’s cruising the reefs of Bonaire.

FIT & COMFORT - Nothing’s worse than an ill-fitting BC. An inflated BC that’s too large wants to rise up and your body (because it’s weighted) wants to go down, and you’ve got something that floats around your ears. A BC that’s too small feels like it’s squeezing the life out of you.

The key areas in the fit of the BC are:

Cummerbund - Should have at least 3" of overlap, slightly more if you’ll also use it for cold-water diving. If you’ll be wearing a weight belt, the cummerbund shouldn’t cover it.

Shoulders - Should adjust snugly (assuming they’re adjustable). If you have to pull the shoulders all the way down, go to a smaller size. If you can’t adjust the shoulders at all, go up one size.

Lapels - When deflated, the lapels of the BC (this only works on a wrap-around design) should touch. If there’s a lot of overlap, go down a size. If they don’t touch when deflated (they’re going to expand as you inflate the BC), go to a larger size.

Length - The bottom of the BC should be somewhere around your hip joint.

Arm holes - They should be wide enough to allow you easy movement, but not so big that the BC will ride up on you.

FIT (PART 2) - There’s a distinction between a warm-water fit and a cold-water fit. In warm water, you wear very little thermal protection so there’s nothing else bulking you up to change the way the BC fits. For warm-water diving, trying the BC on over street clothes is fine.

For cold-water diving, try the BC on with the wetsuit jacket, if the not the jacket and farmer john. Because the wetsuit adds bulk, if you fit the BC with your street clothes, when you take it out for the first dive, it will seem too small.

For both warm-water and cold-water diving, you’ll have to make some trade-offs. If you do mostly cold-water diving, fit the BC that way, and when you use it in warm-water, it will be a bit big. If you do mostly warm-water dives, fit it that way, but realize the BC will seem a little snug for cold-water dives.

FINALLY - Buying a BC is no small investment. Prices run anywhere from $200-650, more if you get into some of the tech models. But spending the right amount of money for a BC that will be comfortable, provide proper buoyancy, and get you adequate floatation, is an investment well worth making.