Losing a diver at sea is one of the worst scenarios any dive operation can face, and in drift diving, the risk is never entirely off the table.
ENOS, short for Elektronisches Notruf- und Ortungssystem, is a German-developed emergency signaling and location system built around that exact situation.
When a diver surfaces away from the boat and starts drifting, they can activate the device to transmit their position to the vessel, giving the crew a GPS coordinate to locate and recover them before conditions make it harder to do so.
But like any safety system, it only works when it is properly maintained and ready to deploy.
6 Essential ENOS Maintenance Tips for Dive Operators
An ENOS beacon that has been properly cared for is one that divers can actually count on. These six steps cover what both individual divers and vessel operators should be doing regularly to keep the system ready.
1. Post-Dive Freshwater Rinse (After Every Dive)
After every dive, give the ENOS beacon a thorough rinse with fresh water to keep it in perfect working condition.
While rinsing, it is also a good moment to quickly check the seams, attachment points, and activation disk before putting the unit away.
2. Drying Before Storage
Once the beacon has been rinsed, let it air dry completely before putting it away.
Storing it while still wet is worth avoiding, and so is leaving it in direct sunlight or exposing it to prolonged heat during the drying process. A cool, shaded spot does the job well enough.
3. Checking Your ENOS for Wear and Damage
Before each dive, take a moment to look the beacon over.
Check the housing for any cracks or impact damage, run a finger along the attachment points and lanyard to make sure nothing has worn through, and test the activation mechanism to confirm it moves freely.
If your operation runs functional LED tests as part of its protocol, this is a good time to do that as well.
4. Secure Attachment Before Entry
Before entering the water, make sure the beacon is securely mounted to a dedicated attachment point, such as a BCD shoulder strap, with the safety lanyard clipped in.
A good rule of thumb is that the device should be reachable with either hand, so that activating it under pressure stays as straightforward as possible.
5. Activation Familiarity
Everyone on board should know how to activate an ENOS beacon, not just the diver wearing it.
The mechanism itself is straightforward: twist the red disk at the bottom cap to activate, and confirm the LED indicator is signaling GPS transmission.
Running through the motion on the surface before the first dive of the day takes less than a minute and means that if the moment comes, nobody is figuring it out for the first time under pressure.
6. Check the Signal Before You Leave the Dock
Before heading out, it is worth doing a quick check to confirm that each beacon shows up on the vessel's receiver. This way, the crew knows every transmitter on board is working and accounted for before anyone enters the water.
When the beacon is activated, it needs to be out of the water to transmit. Hold it as high above the surface as possible, since the higher it sits, the better the line-of-sight transmission to the receiver.
Surrounding conditions can influence how well the signal carries, so both divers and crew should have a basic understanding of this before heading out.
A Well-Maintained ENOS Is a Reliable One
An ENOS beacon that is maintained regularly is one that divers and operators can genuinely count on when it matters. The six steps in this guide are a good starting point, and we can help make sure your operation has the right equipment to back them up.
NRC International has been supplying the ENOS system to dive centers and liveaboards across more than 35 countries since 2000. Whether you are equipping a new operation or replacing aging units, our team can help you find the right setup for your vessel and crew.
Explore our ENOS page and find the right fit for your vessel and crew!
