BCD Inflating by Itself During a Dive – What to Do
A Simple Guide for Divers
Your buoyancy control device (BCD) should only inflate when you press the inflator button.
But sometimes divers suddenly notice something strange:
The BCD slowly inflates by itself, even though the inflator button is not pressed.
This situation can feel confusing underwater, but in most cases it is not dangerous and can be handled easily.
Let's look at what to do underwater and why this happens.
1. What To Do Underwater
If your BCD starts inflating by itself:
1️⃣ Stay calm
A self-inflating BCD is usually not an emergency. The important thing is to control your buoyancy and prevent an uncontrolled ascent.
2️⃣ Disconnect the low pressure inflator hose
The fastest solution is:
- Grab the inflator hose
- Disconnect the low pressure (LP) inflator hose from the BCD
Once the hose is disconnected, no more air can enter the BCD automatically. Your BCD will stop inflating.
3️⃣ Control your buoyancy manually
After disconnecting the hose:
- Add air orally if needed
- Release air using the dump valves
You can safely continue the dive if you feel comfortable.
4️⃣ If necessary, end the dive
If you are unsure or uncomfortable:
- Signal your buddy
- End the dive safely
Equipment problems should always be checked before the next dive. Having an emergency plan helps you respond effectively when things go wrong.
2. Why Does a BCD Inflate by Itself?
The most common cause is a small leak in the inflator mechanism.
Inside the inflator there is a tiny valve system that controls airflow. If sand, salt crystals or wear affect this valve, it may allow a small amount of air to enter continuously. This slowly inflates the BCD.
3. Common Causes
Typical reasons include:
- Sand inside the inflator
- Salt buildup from dried seawater
- A worn inflator valve
- Poorly maintained equipment
- Rental gear used frequently
Even well-maintained BCDs can develop this issue over time.
4. How to Prevent the Problem
There are a few simple habits that reduce the chance of a self-inflating BCD.
Rinse equipment properly
After diving, always rinse the BCD inflator with fresh water. Press the inflator button while rinsing so water can flush the internal valve. For more on equipment care and safety on the boat, see our guide on dive boat safety.
Avoid sand contamination
Try to keep the inflator off sandy surfaces when gearing up. Sand is one of the most common causes of inflator problems.
Test the inflator before entering the water
Before the dive:
- Inflate the BCD slightly
- Make sure air stops flowing immediately when releasing the button
If air keeps entering, the inflator may need servicing.
5. A Small Problem With an Easy Solution
A self-inflating BCD can be annoying, but it is usually easy to control underwater.
Remember the key step:
Disconnect the inflator hose.
Every diver should know this simple trick — it turns a potentially stressful situation into a minor equipment issue.
💡 Tip:
Practice disconnecting and reconnecting the inflator hose on land. In an actual dive situation, the movement should feel natural. If you dive independently, the
Solo Diver
course teaches you to handle equipment issues confidently.
You already learned these skills: Disconnecting the low-pressure inflator underwater, inflating the BCD orally, and maintaining buoyancy – including the fin pivot exercise – were part of your Open Water Diver training. They are standard exercises that make all the difference when equipment acts up. If you haven't practiced them recently, a Scuba Review can help refresh these skills.
🔗 Related Reading
More Tips & Tricks – Practical diving guides and equipment tips
- Water in Regulator – What to do when water keeps entering your regulator
- Emergency Plan – Prepare for unexpected situations
- Solo Diver – Self-reliance and backup procedures
- Dive Boat Safety – Safety on and around the boat
