The BCD, When Good Gear Goes on a Tangent.
The Buoyancy Control Device (BCD), a divers underappreciated safety device! Welcome back to Teaching Tuesday, where we lovingly roast poor diving practices in the name of education and not-drowning.
Today’s lesson: the Buoyancy Control Device (BCD), an incredible piece of gear that can help you float like a majestic manta… or flail like an overinflated party decoration. Let’s talk about gear misuse – because your BCD is a tool, not a floatie from a Spring Break pool party.
What a BCD Should Do:
- Provide controlled buoyancy at the surface and underwater.
- Keep your trim level and your dive calm.
- Let you adjust your buoyancy subtly, not blow up like a parade balloon.
What a BCD Should NOT Do:
- Be filled to the brim like it’s trying to achieve orbit.
- Replace your lungs or your weight system.
- Resemble something a party clown made for a kid named Brayden.
Top Misuses We See in the Wild:
Overinflation at the Surface:
We get it, you want to stay afloat. But unless you’re trying to enter low Earth orbit, there’s no need to inflate your BCD like it’s carrying a small SUV. A few gentle bursts of air will keep you bobbing comfortably. Overdo it, and suddenly you’re flopping around like a hyperactive pool toy, legs kicking, face high above the water, and dignity somewhere on the ocean floor. Balance is key. You want calm control, not an inflatable ego.
Using the BCD as a Depth Control Lever:
Let’s set the record straight: your BCD is not an elevator button. Treating it like a vertical throttle means you’re missing the magic of breathing for buoyancy. Yes, your lungs are literally built-in buoyancy tools, how cool is that? But instead, some divers puff up their BCDs like they’re inflating a life raft, then wonder why they’re rocketing upward or sinking like a brick. Remember: small, intentional adjustments win the buoyancy game. Don’t let your dive become an up-and-down rollercoaster ride.
Using the BCD to Compensate for Poor Weighting:
If you’re wearing so much lead that your BCD is full just to keep you off the sand, you’ve turned yourself into an underwater tug-of-war. That’s not diving, that’s surviving. Think of your weight like seasoning: just enough to get the job done. Too much, and you’re relying on your BCD to fight a battle it was never designed to win. Proper weighting means your BCD works with you, not against physics.
Ignoring the Dump Valves:
You know what’s exciting? A nice, controlled ascent. You know what’s too exciting? Shooting to the surface like a cork out of a champagne bottle because you forgot to vent your BCD. Dump valves are your friends, they’re not just decorative features hanging out on your gear. They’re there to help you release excess air before things get out of hand. Learn where they are. Practice using them, because if you find yourself rocketing upwards wondering what just happened… congratulations, you’ve just become the world’s least graceful surprise breaching whale.
How to Use Your BCD Like a Pro:
- Master neutral buoyancy with breathing first, BCD second.
- Check your weighting – if your BCD looks like a waterbed mid-dive, you’re carrying too much lead.
- Practice using all valves – not just the inflator hose like it’s a magic wand.
- Stay aware – don’t wait until you’re shooting toward the surface to realize you’re inflated like a novelty raft.
Check out this complete guide to BCD maintenance to keep yours functioning safely and smoothly.
BCD Horror Story of the Week: The Great Human Zeppelin Incident
It was a sunny dive day, visibility for days, and our diver, let’s call him “Bob” (because that’s exactly what he did), was ready to make his glorious descent.
Bob was my PADI Advanced Course student. He had a grand total of 5 dives under his belt under another instructor’s tutelage. We had a great briefing and everyone was instructed what to do before we got on the boat and again before the dive. We were on the Mighty St Lawrence river exploring one of the many wrecks. The first dive had a mild current with 65ft depth with a mooring line to follow. Instructions were to inflate bcd, boat staff will confirm. Giant stride in, grab the mooring line then give the ok sign to the boat staff.
I went in first and 2 students followed without issue. Then came Bob.
Bob panicked and thought he was going to die! He inflated his BCD until the dump valve started shooting air by his right ear making him panic even more. Bob couldn’t grab the mooring line because his BCD was acting like an inflated sail, floating so high he could’ve applied for drone clearance, the wind pushing him downstream, legs kicking, arms flailing unable to reach his deflator valve.
Now fully inflated and filled with existential dread, Bob had no idea that I had a firm grip on him and held him next to the mooring line. I reached his inflator and deflated his BCD enough so he was able to breathe again and able to grab the line.
He was fine. But we all learned something important that day:
Don’t become the balloon! Use your gear with intention or prepare to be the cautionary tale at every post-dive beer chat from here to eternity.
Final Thoughts from the Angry Octopus
Your BCD is not a balloon animal. It doesn’t need to squeak, wobble, or be the life of the party. Treat it right, and you’ll have smooth, controlled dives that make other divers nod in quiet respect (and fewer fish giving you side-eye).
Until next week – dive smart, stay wet, and don’t inflate yourself into a nautical piñata.
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