Home Tech Tips Tech Tips: Does Your BCD Fill with Water?

Tech Tips: Does Your BCD Fill with Water?

Alec Peirce show how your BCD fills with water

Hi divers, Alec Peirce Scuba with tech tips… another idea and another thought that might be useful to you. This is another tech tip in direct response to a comment and question so keep them coming! You’re giving me great ideas. So here we go: a tech tip from Scuba 2000 in Toronto! (Wonderful dive store, by the way.)

This particular viewer asked, “My BCD fills with water. Is that normal?” Yeah. That’s normal. BCDs fill with water and that’s the way it is. Let me explain, first of all, why they fill with water; and secondly, if you’re getting a lot of water – maybe too much of it – maybe there’s something you can do about it.

First of all, the BCD by its very construction is a bag. It has a hose on it. You press the blue button and air goes in, giving you buoyancy. When you let air out, you press a button on the end; when air comes out, water tends to go in and down this hose and into the BC. It’s even more pronounced if you use this dump, the quick dump – with most BCs, you pull on the hose and there’s a dump. You can do this with your own BC: you can quickly unscrew the top of the shoulder (don’t lose the rubber gasket!), pull on the handle, and it opens the valve here. This is for control… for letting a little bit of air out… too much and you start to sink.

When you do that, then more water tends to go in. If you unscrew the top – and you can do this on most BCs – you’ll see there’s the valve. When I pull on the cord, the cone seals against the o-ring; when you pull down, the air in the BC rushes out. You can see a big hole down there – as the air rushes out, water rushes in. If you use the BC once, you get a little bit of water; use it twice, you get twice as much. The more you use the BCD, the more water you’ll get in.

Manufacturers have tried to reduce the amount of water. Under the cap that’s screwed on top, if you look closely, you’ll see a little exhaust valve that only works one way: air can rush out but the water coming in is restricted, but it’s not restricted completely. Getting water in your BCD is common. It’s a normal part of operation. How do you stop getting water in the BC? You can’t.

Some divers will come to the surface and they don’t seem to have very much water. Meanwhile, you’re turning yours upside down and dumping it out: it’s got salt and sand in there and pretty soon you’ve ruined your inflator valve. Your divemaster turns it over, and there’s a little bit of water and it’s gone. Why the big difference? It’s simple. It’s because he’s experienced.

BC Valve

If you possibly can, you need to try to control your buoyancy better, so you don’t need to use the BC as much. If you tend to use your BCD a lot – watch yourself during a dive – you’re often putting air in and letting out. Try to slow down and control your buoyancy in other ways. Over time, you’ll get better and better at it.

Alec Peirce of Scuba 2000 with another tech tip! Talk to you soon.

About Alec Peirce:

Alex Peirce 2018 photo

Alec Peirce has been diving for more than 60 years. He is the founder and former owner of Scuba 2000, Canada’a largest dive centre, opening in 1969. He a dive instructor, author, public speaker and former member of the PADI IRRA Advisory Council.

Sea Hunt staring Lloyd Bridges stars Lloyd Bridges as former United States Navy frogman Mike Nelson aired from 1958 – 1961

Alec is recognized as having the worlds largest collection of “Sea Hunt” memorabilia which he shares in this series. … “Sea Hunt” television show is credited with kick starting public interest in the underwater world that evolved into the great sport of scuba diving.

“Alec Peirce Scuba” is dedicated to making your scuba diving easier, safer and more enjoyable through these playlists; “Scuba Tech Tips”, “Vintage Scuba” and “Sea Hunt Remembered”.