The Reef Track RT1 is a dive navigation system that guides divers underwater via a wearable wrist unit and an immobile sensor module. The system comprises a robust wrist display that presents real‑time orientation, distance travelled, and route information, and an inertial measurement unit (IMU) sensor that attaches to the diver’s vest or harness to track movement and heading. Rated to 100 m water depth, the wrist unit features a 2.8‑inch high‑contrast display optimised for visibility in low‑light and deep‑water environments.