We met the Garmin team on a still morning at Fantasy Lake, North Carolina. The water was calm, the air was warm, and in the middle of the dock sat the Garmin Descent S1 Buoy—a bright orange unit that, at first glance, looked like an oversized surface marker.
The plan was simple: deploy it, link it to divers below, and see how it performed. The S1 is designed to act as a surface communication and positioning hub, connecting to Garmin’s T2 tank transmitters and compatible dive computers. On paper, that means live tracking of each diver’s location, depth, and air pressure—along with basic two-way messaging.
Watching It Work
Once in the water, the buoy quickly established GPS position and started relaying data via SubWave sonar. From the dock, we could watch divers’ movements update in real time on a tablet. The combination of triangulated receivers, GPS, and a gyroscope meant the position stayed stable even if the buoy shifted on small waves.
One useful feature was the directional guidance on the diver’s computer—a simple arrow and distance reading pointing back to the buoy. In our calm-water test it felt almost redundant, but in current or low visibility, it could be a genuine help.
Messaging is limited to presets like “Are you OK?” or “Return to buoy.” It’s not voice comms, but it’s functional for quick status checks without hand signals or surfacing.
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After the Dive
Post-dive, the Garmin Dive app displayed a heatmap of each diver’s route along with depth profiles. For training or team debriefs, this is a useful extra layer of information. The buoy’s build feels solid—rated to IPX8, waterproof to 33 feet (10 m), and with a 15-hour battery life that covers a full day of diving.
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The Trade-Offs
The biggest hurdle is cost. The buoy itself retails for $2,499.99 USD, but that’s just the start. Each diver needs a T2 transmitter, and for full functionality, a compatible Garmin dive computer. Outfitting a team can add up quickly.
There’s also the question of who really needs it. Search-and-rescue, military, or specialized training teams could make good use of this kind of live data. For most recreational operations, the price and complexity are hard to justify.
While you can run multiple transmitters with just one connected dive computer, it’s a fiddly setup and not something most dive shops will want to deal with.
Where It Makes Sense
This isn’t a mass-market gadget—it’s a specialized kit for situations where knowing exactly where each diver is, and how much gas they have left, really matters. The positioning technology is the standout here, and it will be interesting to see if Garmin eventually applies it to more accessible models.
For now, the Garmin Descent S1 Buoy is best seen as a tool for a specific corner of the diving world. Our time with it at Fantasy Lake showed it works as intended, but whether it earns a spot on your boat comes down to your budget and the kind of diving you do.
Take a moment to look at this.
