Garmin SubWave™ is a sonar-based wireless system that lets compatible Garmin dive computers (paired with a Descent™ T2 transceiver) exchange preset messages, send and receive air-integration data, and relay diver location/depth information to a Descent™ S1 Buoy on the surface. It enables diver-to-diver messaging up to ~30 m, diver-to-surface messaging and monitoring through the S1 Buoy up to ~100 m (range varies with conditions), and tank-pressure/depth monitoring within closer ranges when using Descent T2 transceivers.
What is SubWave™ sonar technology?
SubWave™ is Garmin’s underwater, short-range sonar networking technology. Instead of Bluetooth or radio (which don’t travel well underwater), SubWave uses sound pulses — sonar — to carry small packets of data between devices. That lets divers who are wearing compatible Garmin dive computers (and who have a Descent T2 transceiver paired to their cylinders) exchange preset messages, broadcast tank pressure and depth, and allow a surface buoy (the Descent S1) to act as a relay and tracker for topside crews.
How SubWave works
- Each diver wears a compatible Garmin Descent dive computer (Mk3i, X50i, etc.) and a Descent T2 transceiver is fitted to the cylinder. The T2 measures cylinder pressure and sends that data to the diver’s computer via SubWave.
- Divers can send preset messages to each other when within sonar range (roughly 30 m).
- If a Descen S1 Buoy is deployed on the surface, it extends messaging and monitoring range — letting topside crews track divers’ pressures, depths and locations and send/receive messages up to about 100 m from the buoy (actual performance depends on sea state, thermoclines, obstacles and diver orientation).
Compatibility and features
| Device | Diver-to-Diver | Diver-to-Surface (with Descent™ S1 Buoy) |
|---|---|---|
| Descent™ Mk2i + Descent T2 |
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| Descent Mk3i or Descent X50i + Descent T2 |
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Use cases — who gains the most?
- Dive operators and charter boats: real-time monitoring and automatic low-air alerts let crews intervene faster and log diver activity. Heatmaps help with repeat-trip planning.
- Dive instructors and training courses: quick messaging (“watch for my signal”, “safely end dive”) reduces confusion during skills sessions and large groups.
- Technical divers and survey teams: being able to monitor multiple tanks and log exact locations/depths helps with planning staged decompression and complex tasks.
- Recreational groups and buddy teams: easier to keep tabs on each other and call for help if needed; navigation back to the buoy avoids search/recall delays.
Practical tips for getting the best from SubWave
- Keep firmware updated. Garmin occasionally updates SubWave features and compatibility — check the support pages and update both dive computer and T2 firmware before a trip.
- Position the buoy well. For best results, deploy the S1 Buoy upwind/up-current of the expected exit and in a place with a clear acoustic path (avoid dropping it too close to noisy engines).
- Check transceiver battery levels pre-dive. T2 battery status is available and should be checked so tank telemetry doesn’t drop mid-dive.
- Practice preset messaging before you need it. Make sure students or buddies know which presets map to which real-world actions (e.g. “Need more gas” vs “Need to ascend” — they sound similar but imply different responses).
- Use the buoy for groups. If you run charters, make S1 Buoy deployment standard practice on busy days — it extends range and gives a single source of truth for your topside team.
FAQ
Q: Do I need anything other than the S1 Buoy to use SubWave?
A: Yes — divers need compatible Garmin Descent dive computers and Descent T2 transceivers fitted to their tanks to share air integration data; the buoy extends messaging/monitoring to the surface.
Q: Will SubWave give me GPS locations underwater?
A: No — GPS does not work underwater. The buoy provides surface GPS and the system can approximate diver locations relative to the buoy using sonar data while submerged; the buoy’s GPS logs surface positions.
Q: Can I customise messages?
A: SubWave uses a set of preset messages designed for clarity underwater; you can set favourites for quick access, but free-text messaging is not used (to keep transmissions short and reliable underwater).
For those who love exploring deeper together, we created the Garmin Prestige Yacht Safety & Dive Communication Bundle — built around SubWave™ technology for seamless underwater connection, plus the inReach satellite system for peace of mind on the surface. It keeps divers and crews in sync with real-time depth, tank pressure, and location data, while ensuring you’re covered in case of emergencies. Designed for pros, explorers, and ocean crews who want smooth dives and total situational awareness, below and above the water.
Final thoughts
SubWave transforms the way dive groups operate by turning previously noisy, ambiguous communications into concise datapoints and preset messages. For dive operators, instructors and large groups, that means faster responses, better tracking and clearer on-water decision making. For recreational buddies, it means better situational awareness and an easier route back to the boat. When you pair a Descent S1 Buoy with Descent T2 transceivers and compatible Descent dive computers, you get a connected diving system designed to improve safety and coordination — with the clear caveat that no electronic system replaces solid training and dive planning.
