Garmin's new diving buoy is designed to improve underwater communication

Siri Schubert

17.7.2025

Translation: machine translated

Miscommunication, poor visibility and navigation errors - these are some of the biggest risks when diving. Garmin's Descent S1 diving buoy enables messages to be sent underwater and is designed to make diving safer.

Garmin has added a new tool to its Descent dive computer series: the S1 buoy. Thanks to it, sports and recreational divers will be able to exchange messages with each other and with the crew. They will also be able to keep an eye on the distance to the buoy and other relevant information.

The buoy communicates via radio, Wi-Fi and compatible dive computers

The Garmin buoy uses a proprietary radio technology, the subwave sonar network. This allows the crew to communicate from the boat with up to eight divers within a radius of 100 metres. On the surface, the buoy connects to the Garmin Dive app via WLAN to transmit information about the dive. Underwater, divers can send each other pre-formulated messages and see their distance from the buoy.

Provided they have the right computers and transponders. According to Garmin, the dive computers «Descent Mk3i» and the «Descent X50i» work best. The Garmin models «Descent Mk2i +» and the transceiver «Descent T2» can receive messages but not send them.

More information on the range of the buoy and the options for connecting it to Garmin dive watches can be found here. We do not currently have any of the compatible models in our range, but you can find other Garmin dive computers from the Descent series here.

How divers benefit from the buoy

If you are connected to the buoy via your dive computer and the Garmin Transceiver T2, you can, according to Garmin:

• Navigate back to the buoy The distance to the buoy and the direction can be seen on your dive computer. If you lose your bearings during the dive, you can use this to find your way back to the base

• Send messages to the boat crew Divers can tell the team on the surface where they are, where they are diving to, how long their decompression time is and whether they need to surface earlier.
• ** Send messages to other divers** If your dive buddies are within 100 metres of you, you can send them preset messages if you lose sight of them.
• Analyse your dive In the Garmin Dive app, you can view where you dived and how long you spent at certain locations after the dive.

What advantages the system has for the crew on the boat

Stressed looking for bubbles on the surface or signal buoys to locate divers? The S1 buoy puts an end to this. Because with it, the boat team can:

• Tracking the position of divers Up to 100 metres away from the buoy, the boat crew can see approximately where the divers are.
• Send messages to the depths If the weather changes or other events require a quick return to the boat, the team can send messages from the boat and call divers back. They can also communicate with people underwater via other preset messages.
• Send alerts if the cylinder pressure is too low or the depth is too great The crew on board can use the Descent T2 transceiver to monitor whether the agreed minimum cylinder pressure or depth limit has been exceeded. If there are any problems, the team on the surface automatically receives an alarm signal.

Battery life, weight and price

According to Garmin, the buoy weighs less than one kilo and is waterproof to a depth of ten metres (IPX8). To connect to the Garmin Dive app, it uses its own Wi-Fi with a range of up to 60 metres. This manufacturer video gives an insight into how it works.

We do not currently have the Garmin S1 buoy in our range. According to Garmin, it costs around 2500 francs. It could be useful for diving schools, clubs and private diving groups that already use compatible dive computers from the Garmin Descent series to supplement and improve underwater safety and communication.

Siri Schubert

Senior Editor

Siri.Schubert@digitecgalaxus.ch

Research diver, outdoor guide and SUP instructor – I love being in, on and around water. Lakes, rivers and the ocean are my playgrounds. For a change of perspective, I look at the world from above while trail running or flying drones.

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