Wrist computer or watch-style?
Both go on your wrist and do the same job underwater. The difference is size, and whether you’ll wear it when you’re not diving.
- Wrist computers have a bigger screen and bigger numbers, and are made for diving only. Examples: the Shearwater Peregrine and Peregrine TX (a 5.59 cm, 2.2 inch colour screen), the Suunto Zoop Novo and the Mares Puck 4.
- Watch-style computers (often searched for as “dive watches”) are small enough to wear every day. Some are also smartwatches and sports watches: the Garmin Descent G2 and Descent Mk3 and the Suunto Ocean add GPS, heart rate and sport modes. Others are dive-focused in a watch size, such as the Suunto Nautic S, Shearwater Teric, Shearwater Tern TX and Mares Sirius.
A watch that’s only water-resistant isn’t a dive computer. Look for dive modes and a decompression algorithm in the listing.
Prefer your computer on a hose? Consoles such as the Suunto CB-2 Zoop Novo combo put a computer beside a pressure gauge.
Air integration and tank transmitters
An air-integrated computer shows your tank pressure, and on some models your gas time remaining, without a pressure gauge on a hose. A small transmitter fits on your regulator’s first stage and sends the pressure to your wrist.
- Shearwater Peregrine TX: up to 4 transmitters, with sidemount support. Pairs with the Shearwater Swift, or buy both as the Peregrine TX + Swift bundle.
- Suunto Ocean: up to 5 Suunto Tank PODs. The Suunto EON Core reads up to 10.
- Mares Quad Ci and Mares Sirius: up to 5 transmitters each. The Sirius pairs with the Mares Sirius LED tank module 2.0.
- Garmin Descent Mk3i and Descent X50i: with the Descent T2 transceiver.
Transmitters are sold separately and pair with their own brand’s computers. Each transmitter’s page lists which models it works with. A computer without air integration, such as the Peregrine, works with the pressure gauge on your regulator.
Nitrox
Nitrox (enriched air) lets you stay longer at recreational depths. If you plan to do the nitrox course, check the computer handles the mixes you’ll use.
- One nitrox mix: most computers in the range. The Suunto Zoop Novo takes 21–50% oxygen, the Mares Smart Air 21–99% and the Suunto Ocean 21–100%.
- Several gases: the Peregrine and Mares Puck 4 switch between up to 3 gases.
- Trimix and rebreathers: technical computers such as the Shearwater Perdix 2 Ti, Teric, Suunto EON Core and Garmin’s Descent range.
The screen
- Colour screens show more at once and can be set up the way you like: the Peregrine’s 2.2 inch LCD, the AMOLED screens on the Perdix 3 (2.4 inch), Suunto Nautic S and Garmin Descent G2, and the Cressi Da Vinci’s colour LCD.
- Segment and dot-matrix screens are simple and high-contrast: the Mares Puck 4, Mares Smart Air and Suunto Zoop Novo.
Bigger is easier to read in dim water or without your glasses; a watch-sized screen is easier to live with every day. Try reading one at arm’s length in the shop.
Charging or a replaceable battery
- Rechargeable: charge it like a phone. The Peregrine and Peregrine TX charge wirelessly and last up to 30 hours of diving; the Garmin Descent G2 up to 27 hours in dive mode; the Suunto Ocean and Cressi Da Vinci charge by USB cable, and the Suunto EON Core and Tusa TC1 are rechargeable too. Pack the charger on a dive trip.
- Replaceable battery: swap it yourself and keep diving. The Suunto Zoop Novo, Mares Puck 4 and Cressi Donatello have user-replaceable batteries, and the Tusa Element III takes a CR2450 coin battery. The Shearwater Perdix 3 runs on a single AA, handy on remote trips.
For new divers
Look for big numbers, a few buttons and air and nitrox modes. You don’t need multi-gas or trimix to start.
- Suunto Zoop Novo: a big backlit screen and a simple menu.
- Mares Puck 4 and Mares Smart Air: clear segment displays; the Smart Air can add a tank transmitter later.
- Cressi Donatello and Tusa Element III: air and nitrox in a simple wrist computer.
- Tusa TC1: a rechargeable wrist computer with a straightforward display and menu, and scuba, freediving and gauge modes.
- Shearwater Peregrine: a big colour screen and Shearwater’s easy interface, with room to grow into gas switching.
Still learning? Your instructor on the Open Water course can show you how a computer works before you buy.
For experienced divers
Once you dive often, travel to dive or head deeper, air integration, a compass, more gases and a battery that lasts the trip start to matter.
- Shearwater Peregrine TX: air integration, compass and sidemount support on a big colour screen.
- Shearwater Perdix 3: a full-size computer for recreational, technical and rebreather (CCR) divers.
- Shearwater Teric, Garmin Descent Mk3i and Suunto Nautic S: watch-sized, with air integration and technical modes.
- Suunto Ocean and Garmin Descent G2: for divers who also want a sports watch.
Freediving too? The Suunto Ocean, Garmin Descent G2 and Suunto Zoop Novo have freediving modes, the Mares Smart Apnea is made for freediving and spearfishing, and the Cressi Neon is a small scuba and apnea watch-computer.
Try one on
Fit and how easily you can read the screen matter more than a feature list. Come in to our St Peters or Manly dive centre to try computers on and ask questions, or browse every dive computer in the shop.
