Shearwater

The Shearwater range at Oyster

Shearwater have built their reputation on one thing: putting the numbers that matter where you can read them, and getting everything else out of the way. The interface stays consistent across the range, so moving from a first recreational computer to a technical one does not mean relearning how to read your deco. We stock the line end to end, from single-gas recreational units through to open and closed circuit technical computers, plus the transmitters and straps that go with them.

Recreational: Peregrine, Peregrine TX and Tern

The Peregrine is the natural first Shearwater. It runs air, single-gas nitrox and multi-gas nitrox on a 2.2 inch full-colour LCD, charges wirelessly, and carries full decompression support with Buhlmann ZHL-16C and gradient factors underneath, so it will not become the limiting factor when your training moves on. It also will not lock you out after a missed decompression stop. The Peregrine Adventures Edition is the same computer in Light or Dark colourways with a matching ballistic nylon travel case.

The Tern takes a different shape: a compact watch-style unit with a 1.3 inch AMOLED display, Air, Nitrox, 3 Gas Nitrox, Gauge and Freedive modes, and Remora quick connect bands. It is designed and built in Canada, meets EN dive compliance standards and is depth-rated to 120 metres. The Tern TX adds a digital compass and connects to up to four Swift transmitters.

The Peregrine TX sits between the two ideas. You get the Peregrine display and the same straightforward modes, plus air integration for up to four transmitters and a tilt-compensated 3-axis digital compass. Like the Peregrine, it will not lock out after a missed stop.

Technical: Perdix 2 Titanium and Perdix 3

The Perdix 2 Titanium is the established open and closed circuit technical computer here. It supports up to five gases including trimix, runs Buhlmann ZHL-16C with user-adjustable gradient factors, and seals its battery compartment behind a dual O-ring cap. It runs on a single AA battery.

The Perdix 3 is the newer full-size platform: a 2.4 inch AMOLED display, a precision-engineered titanium bezel, and titanium piezo-electric buttons with no moving parts and no O-ring penetrations, which removes one of the more common failure points on a dive computer. It carries seven dive modes including OC Tec, CC/BO with fixed PPO2, Gauge and Freediving, supports up to four transmitters at once, works with GPS transmitters, and is rated to 260 metres. Like the Perdix 2 Titanium it takes a user-replaceable AA battery, which is rather the point: you can be two days into a liveaboard with a dead cell and still dive.

Watch-style: Teric

The Teric is the one you can wear off the boat. A bright AMOLED screen under a sapphire crystal, open circuit, closed circuit, trimix, gauge and freediving modes, a rechargeable battery with wireless charging, and air integration for up to two transmitters. It comes in black, silver and blue, with optional multi-colour straps. The Bronze Teric Journeys Edition is the same flagship computer with a bronze bezel drawn from traditional dive helmets, a black strap, and a ballistic case sleeve carrying an underwater motif.

Air integration and the Swift transmitters

Air integration puts tank pressure on the same screen as your depth, time and deco ceiling, with no high-pressure hose running to your wrist. The Swift is Shearwater's transmitter for that job. It uses a collision-avoidance system so several units can work alongside each other on a busy boat, takes a user-replaceable battery, and pairs with Shearwater's air-integrated computers.

The Swift GPS does the same and adds position. It captures dive site coordinates at entry and exit automatically and pushes them into your Dive Shearwater log, where dives appear on a map with coordinates and, where available, the location name. It is compatible with current Shearwater air-integrated computers, including the Perdix 2 Titanium, Peregrine TX, Teric and Tern TX, and it shares GPS data with nearby Shearwater computers, which is useful across a buddy pair or a boat. Transmitters are sold separately from the computers.

What Shearwater does differently

Two things, mainly. The first is the algorithm. The decompression-capable models here run Buhlmann ZHL-16C with gradient factors, and the conservatism is something you set to suit your training and your profile rather than a proprietary model you cannot see into. The second is that the Peregrine and Peregrine TX will not lock you out after a missed decompression stop, which means the computer keeps giving you information at exactly the moment you most need it.

The rest follows from that. Dive logs go over Bluetooth to Shearwater Cloud, and firmware updates arrive the same way, so a computer you buy now keeps improving on your wrist. Alerts are vibration-based as well as visual, which matters when you are hooded and looking somewhere else. And display quality across the AMOLED models is not cosmetic: staying legible in poor visibility or bright tropical light is a safety feature, not a specification.

Straps, batteries and living with the kit

The battery decision is worth making before you buy rather than after. The Perdix 2 Titanium and Perdix 3 take a standard AA cell you can change in minutes, anywhere in the world. The Peregrine, Peregrine TX and Teric charge wirelessly, with no proprietary cable to lose or leave on a kitchen table. Neither approach is wrong. They suit different kinds of trip.

Straps are straightforward on all of them. We stock replacement Peregrine straps in black, white and ocean blue, the Peregrine ships with a bungee cord strap kit if you dive dry, the Teric takes optional multi-colour straps, and the Tern and Tern TX use Remora quick connect bands you can swap without tools to change length or colour.

Oyster Diving Shop is a PADI dive and travel centre and an authorised Shearwater dealer, staffed by working divers. If you want help matching a computer to the diving you actually do, or checking transmitter compatibility before you order, ask us.