GARMIN Descent S1 — A Breakthrough in Underwater Team Communication

In 2025, the Editor had the privilege of attending the 2025 Garmin Dive Club Asia Gathering (referred to hereafter as the G/D/C event) as a staff member. Hosted by Garmin, this landmark gathering brought together Garmin Dive Club VIPs from eight countries across Asia. The event was designed to foster face-to-face connection, sharing the unique appeal and cutting-edge technology of Garmin's products while creating an extraordinary experience for diving enthusiasts.

Group photo of all participants at the 2025 G/D/C event

The event featured Garmin brand ambassadors from across the region, each bringing an impressive wealth of professional experience. Garmin also welcomed distinguished guests including Thailand's renowned technical diver Por Parasu and celebrated Filipino underwater photographer Ram Yoro, who joined attendees for an in-depth exchange on diving technique and experience. From product highlights to real-world applications, the event was a source of inspiration for all involved, igniting boundless enthusiasm for the intersection of diving and technology.

Garmin SubWave Technology's Newest Highlight — Garmin Descent S1

Garmin Product Manager introducing the GARMIN Descent S1 at the G/D/C event

At this event, Garmin divided sessions into scuba diving and freediving tracks, with dedicated product managers presenting the practical features Garmin has developed for each discipline. But the undisputed highlight of the entire G/D/C event was the debut of the latest technological application in the Garmin SubWave product line — the Garmin Descent S1 — set to deliver an entirely new underwater and surface communication experience for divers.

The Garmin product lineup alongside the Descent S1

SubWave Sonar Technology: Redefining Underwater Communication

At the heart of the Descent S1 is Garmin's proprietary SubWave sonar technology — a sonar-based communication system that fundamentally transforms how divers interact underwater and with the surface. SubWave works seamlessly with compatible Garmin devices such as the Descent Mk3i and X50i, and with the addition of a T2 transmitter, divers using different models can communicate with ease. SubWave leverages sonar sound waves to transmit data, dramatically extending coverage — message transmission, scuba tank pressure readings, and depth monitoring are supported up to 100 meters, for groups of up to 8 divers.

Descent S1: Bridging the Underwater and Surface Worlds

Before entering the water, all divers perform signal pairing and confirmation

The Descent S1's breakthrough innovation lies in enabling real-time communication between underwater divers and the surface through a buoy system. This three-sensor buoy floats on the surface and communicates bidirectionally with divers' Garmin watches, delivering live data to both divers and their surface support team. Key highlights include:

Underwater Situational Awareness: Garmin dive computers paired with the Descent S1 buoy display a data field showing the buoy's distance and direction (indicated by a blue arrow). This streamlines navigation back to the starting point, even in strong currents or low-visibility conditions. During the event, the Garmin product manager shared his personal experience using the Descent S1 at a dive site in California — despite facing strong currents, he was able to follow the indicator and return effortlessly to the buoy's location.
Surface Monitoring: The surface team can sync with the buoy via the Garmin Dive mobile app to monitor divers' positions, tank pressure, and depth in real time. This enhances safety oversight, allowing surface personnel to confirm diver locations at any moment.
Surface-to-Diver Messaging: The surface team can also send preset messages to underwater divers through the Garmin Dive app, making it easy to relay changing surface conditions at any time. Divers can likewise update the surface team on their dive status, with two-way communication boosting overall team safety.
Dive Visualization: After a dive, divers can review a heatmap within the Garmin Dive app showing the underwater areas they explored. This aids future navigation and generates a shareable dive record.

Surface teams monitor diver status via iPad or iPhone.

The heatmap record that appears in the Garmin Dive dive log after a dive is completed

The Descent S1 buoy extends SubWave's communication range to 100 meters of line-of-sight distance — a significant improvement over the 30-meter diver-to-diver messaging range. That said, the Garmin product manager noted that water density, thermoclines, or physical obstacles (such as rocks or wrecks) may affect signal clarity, though the system continues to function in low-visibility conditions.

Overcoming Challenges

The Garmin team noted that ensuring reliable signal transmission in marine environments was one of the major challenges in developing SubWave and the Descent S1. Rigorous testing was conducted across a wide range of conditions, including low-visibility waters, to ensure the system's robustness. The Garmin product manager mentioned that the buoy uses a narrow-band acoustic wave design that reduces interference from external noise sources such as boat motors.

Ensuring reliable signal transmission in marine environments was one of the key challenges in developing SubWave and the Descent S1

Garmin's Vision and Aspirations for SubWave

SubWave technology was born from Garmin's desire to go beyond traditional diving communication systems — which are typically constrained by limited range or prohibitively expensive military-grade solutions. The Garmin product manager emphasized that SubWave creates an entirely new category for consumer-level divers, making advanced communication accessible and affordable. The Descent S1 marks a significant milestone as the first product to enable real-time diver-to-surface communication for consumer divers — a capability previously reserved for professional or military applications.

Looking ahead, Garmin plans to further integrate the Descent S1 into its marine product ecosystem — for example, connecting it to vessel chartplotters or other marine electronics to unlock additional functionality. The team is also exploring applications for competitive freediving and pool training, responding to user demand for features tailored to those settings.

The Garmin product lineup comprehensively meets the safety needs of all types of divers, delivering professional, reliable solutions.

Garmin's philosophy is to create products that not only enhance safety and situational awareness but also maximize the joy of diving. With the Descent S1 and SubWave, Garmin empowers divers to dive without worry, focusing entirely on exploration and creating unforgettable memories. Garmin remains committed to continuous innovation, actively gathering user feedback to refine and expand the ecosystem's capabilities.

Garmin empowers divers to dive without worry, focusing on exploring the ocean and creating unforgettable memories

Who Is the Descent S1 Best Suited For?

While the Garmin Descent S1 is positioned at a more accessible price point, the cost remains relatively steep for the average recreational diver. Furthermore, the Descent S1's core functionality depends on every team member being equipped with compatible watches and transmitters in order to fully leverage its SubWave sonar communication and data-sharing capabilities. The Garmin products currently supporting SubWave transmitters — such as the Descent Mk3i and X50i — are high-end, premium devices, meaning the total investment required to outfit an entire team is considerable. Additionally, enabling surface monitoring requires at least one surface team member to operate the app and deploy the Descent S1 buoy — a setup that is rarely feasible in typical recreational diving scenarios.

When a team is fully equipped with Garmin Descent products featuring SubWave, the Descent S1 can perform at its fullest potential

For these reasons, the Editor believes the Descent S1 is best suited for team-oriented applications — such as underwater engineering crews, underwater film production teams, or marine research units. These professional teams typically have sufficient resources to invest in advanced technology that meaningfully improves operational safety and collaborative efficiency, allowing them to fully harness the potential of the Descent S1 and SubWave sonar technology.

Conclusion

We believe Garmin will continue leading divers into new experiences, powered by technology

The Garmin Descent S1 represents a revolutionary step forward for divers, combining the capabilities of a high-end dive computer with the versatility of a smartwatch. Its SubWave sonar technology sets a new standard for underwater communication, offering extended range, real-time data sharing, and a direct link to the surface. With features such as preset messaging, tank pressure monitoring, and buoy navigation, the Descent S1 enhances both safety and situational awareness while making the dive experience more enjoyable and memorable.

Garmin's ambitions for SubWave are bold — aimed at redefining how divers interact with the underwater world and the surface above. By closing the gap between consumer-grade and professional-grade technology, the Descent S1 and SubWave pave the way for a more connected, more immersive diving experience. As Garmin continues to innovate and incorporate user feedback, the future of dive technology looks brighter — and deeper — than ever.