The Shearwater Tern is a watch-style dive computer built for recreational and sport divers, designed and tested as Shearwater's most compact model. It runs a 1.3-inch AMOLED display with toughened glass, giving clear visibility across a range of lighting conditions underwater. The computer is depth rated to 120m and tested to EN engineering standards for dive computer compliance, though its intended use sits with recreational and entry-level diving rather than technical profiles.

The Tern supports five dive modes: Air, Nitrox, 3-Gas Nitrox, Gauge, and Freedive. It does not include mixed-gas technical or closed-circuit rebreather modes, which are reserved for Shearwater's Perdix 2, Teric, and Petrel 3 models. The unit is rechargeable via USB-C wireless charging, with a rated battery life of up to 20 hours of dive time per charge, and includes a customisable vibration alert system alongside Bluetooth connectivity for syncing dive logs through the Shearwater Cloud app. It ships with Shearwater's Remora quick-connect bands and webbing straps, allowing strap length and colour to be changed without tools.

The base Tern model is not transmitter-capable and does not include a digital compass. Divers who want wireless air integration, connecting to up to four Swift transmitters for real-time gas pressure data, should look at the Tern TX variant, which also adds a built-in digital compass. Both models share the same display, dive modes, depth rating, and charging system; the difference is air integration and compass functionality. Divers anticipating a move into full technical or CCR diving should consider the Teric, Perdix 2, or Petrel 3 instead, as the Tern range is positioned for recreational use.