Bubble Check: How to Spot Gear Leaks Before a Dive

A diver with air leaks all over the place

Every dive should include a bubble check as part of your pre-dive routine. A bubble check is your last chance to spot gear failures before a dive. Even a small leak can indicate a failed O-ring, loose connection, or hose damage. Catching a leak before descent can prevent gas loss, freeflows, or regulator failures underwater.

When to Perform a Bubble Check

Shore Dive: Best done before descent while standing in chest-deep water.
Boat Dive: Perform it immediately after water entry.
Mid-Water Check: If unsure, ask your buddy to check you during descent.

How to Ask for a Bubble Check (Hand Signals)

Point at yourself ("Me").
Point at your eyes ("Look").
Pinch your fingers together ("Bubbles").
Point behind you ("Check my back").

How to Perform a Bubble Check (Step-by-Step)

Both divers submerge slightly (kneeling in shallow water or hovering mid-water). The diver being checked slowly spins while their buddy examines these key failure points:

Chest: BCD inflator hose, drysuit inflation valve.
Left Side: SPG connection and hose.
Back: First stage, hoses, and tank valve (especially O-rings on yoke valves).
Right Side: Primary regulator, alternate air source (octo or backup reg).
Signal OK or point at leaks using the "pinching" motion to indicate bubbles.

What If You See Bubbles? When to Call the Dive

Check your tank O-ring before diving. A minor leak at the tank valve often means an O-ring is starting to fail.
Air trapped in BCD/Wing fabric (harmless).
A few bubbles escaping from a not fully tightened hose connection.
Hose leaks often worsen over time. Even a small leak today could lead to a total failure on a future dive.
Bubbles from regulator hoses (could mean pinholes or a failing crimp).
Steady leaks from the first stage or tank valve (failed O-ring or loose connection).
Any air escaping at a rate that changes SPG pressure.

"I personally call a dive for any bubbles on my gear. However, some divers accept minor leaks, such as bad tank O-rings. This is a personal risk decision."

Example of a Bubble Check

Below is a perfect example of what bubbles look like under water. Well done to @jadescubaadventures over on Instagram.

Final Thoughts: Bubble Checks Prevent Equipment Failures

Make bubble checks part of your routine to catch problems before they become emergencies. If you find a leak, fix it before diving or abort the dive.

Want to refine your gear setup? Check out our guide to setting up a Balanced Rig.