GARMIN Descent S1 — The New Dive Communication Tool Built for Team Operations, a New Breakthrough in Dive Technology

In 2025, the Editor had the privilege of participating as a staff member in the 2025 Garmin Dive Club Asia Gathering (hereinafter referred to as the G/D/C event) — a grand gathering hosted by Garmin, bringing together Garmin Dive Club VIPs from 8 countries across Asia. The event was designed to foster face-to-face exchange, sharing the unique appeal and cutting-edge technology of Garmin products, and creating a one-of-a-kind experience for diving enthusiasts.

The event featured specially invited Garmin brand ambassadors from various countries, each with an impressive professional background. Garmin also had the honour of welcoming distinguished guests including renowned Thai technical diver Por Parasu and celebrated Filipino underwater photographer Ram Yoro, who joined participants in an in-depth exchange of diving techniques and experiences. From product features to real-world applications, the event inspired all attendees and ignited boundless enthusiasm for the fusion of diving and technology.

Garmin SubWave Technology's Newest Highlight — Garmin Descent S1

At this event, Garmin divided the sessions into scuba diving and freediving segments, with different product managers introducing the practical features Garmin has developed for each discipline. However, the most important highlight of the entire G/D/C event was undoubtedly the debut of the latest technological application in the Garmin SubWave product line — the Garmin Descent S1 — set to deliver a brand-new underwater and surface communication experience for divers.

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 the way 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 uses sonar sound waves to transmit data, dramatically extending coverage — messaging, scuba tank pressure, and depth monitoring are supported at distances of up to 100 m, for a team of up to 8 divers.

Descent S1: Bridging the Underwater and the Surface

The breakthrough innovation of the Descent S1 lies in enabling real-time communication between the underwater world and the surface through a buoy system. This buoy, equipped with three sensors, floats on the surface and maintains two-way communication with divers' Garmin watches, delivering real-time data to both divers and their surface support team. Key highlights include:

• Underwater situational awareness: A data field appears on the Garmin dive computer paired with the Descent S1 buoy, indicating the buoy's distance and direction (shown as a blue arrow). This feature simplifies navigation back to the starting point, even in strong currents or low-visibility conditions. During the session, the Garmin product manager shared his experience using the Descent S1 at a dive site in California — despite facing strong currents, he was ultimately able to follow the indicator and return to the buoy's position with ease.
• 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 monitoring, allowing surface personnel to confirm diver locations at any moment.
• Surface-to-diver messaging: The surface team can also communicate with underwater divers through preset messages in the Garmin Dive app, making it easy to relay surface conditions at any time. Divers underwater can likewise inform the surface team of their dive status, with two-way communication enhancing overall team safety.
• Dive visualisation: After a dive, divers can review a heat map in the Garmin Dive app showing the underwater areas they explored. This not only aids navigation but also generates a shareable dive record.

The Descent S1 buoy extends SubWave's communication range to 100 m line-of-sight distance — a significant improvement over the 30 m messaging range between divers. However, 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 normally in low-visibility conditions.

Overcoming Challenges

The Garmin team shared that one of the biggest challenges in developing SubWave and the Descent S1 was ensuring reliable signal transmission in the marine environment. They conducted rigorous testing under a variety of conditions, including low-visibility waters, to ensure the system's robustness. The Garmin product manager noted that the buoy uses a narrow-band sonar design to minimise interference from external noise sources such as boat motors.

Garmin's Vision and Expectations for SubWave

SubWave technology was born out of Garmin's desire to go beyond traditional dive communication systems, which are typically limited by range or confined to expensive military-grade solutions. The Garmin product manager emphasised that SubWave creates an entirely new category of application for consumer-level divers, making advanced communication accessible and affordable. The Descent S1 represents a significant milestone — the first time real-time communication between a diver and the surface has been made available to consumer-level divers, a capability previously reserved for professional or military use.

Looking ahead, Garmin plans to further integrate its marine product ecosystem — for example, by connecting the Descent S1 to vessel chartplotters or other marine equipment to enhance derived functionality. The team is also exploring applications for competitive freediving and pool training, responding to user demand for features tailored to these scenarios.

Garmin's philosophy is to create products that not only enhance safety and situational awareness, but also maximise the joy of diving. Through 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 capabilities of its ecosystem.

Target Audience Analysis for the Descent S1

While the Garmin Descent S1 is positioned at a more accessible price point, its cost may still feel relatively high for the average recreational diver. Furthermore, the core functionality of the Descent S1 relies on the entire team being equipped with compatible watches and transmitters in order to fully leverage its SubWave sonar communication and data-sharing capabilities. Garmin products currently supporting SubWave transmitters — such as the Descent Mk3i and X50i — are high-end devices, making the investment required to outfit an entire team quite considerable. At the same time, achieving surface monitoring requires at least one surface member operating the app and deploying the Descent S1 buoy on the surface, a scenario that is practically difficult to realise in typical recreational diving settings.

For these reasons, the Editor believes the ideal target audience for the Descent S1 is primarily "team-oriented" users — such as underwater engineering crews, underwater film production teams, or underwater scientific research units. These professional teams typically have greater resources at their disposal, and by adopting advanced technology they can effectively enhance operational safety and collaborative efficiency, fully realising the potential of the Descent S1 and SubWave sonar technology.

Conclusion

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

Garmin's ambitions for SubWave are bold — aimed at redefining the way divers interact with the underwater world and the surface. By bridging the gap between consumer-level 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.

Further Reading

• GARMIN Descent S1 Official Product Page
• The Adventure Essential for Diving Enthusiasts! Garmin X50i Unboxing: Square Screen and Technical Diving Features Revealed
• 【What's This Gear #26】GARMIN Mk3i Real-World Unboxing: Messages + Tank Pressure + Horizontal Distance — Monitor Your Team's Status, Underwater Research Safety Up Up
• GARMIN Mk3i + T2 Transmitter, the World's Most Powerful, Further Evolved! Underwater Messaging and Tank Pressure Monitoring Solution