The best dive computer

Andrew Hard

Scuba certification involves three main steps -- knowledge development, confined water dives, and open water dives. Begin your journey at any reputable dive shop accredited by the Professional Association of Diving Instructors (PADI).

From the outside, scuba diving can seem like an overwhelming hobby. Diving requires the precise monitoring of things such as depth, time, temperature, navigation, gas levels, and vital signs. Not only that, you have to calculate how long you can stay at each depth and schedule safety stops, otherwise you risk serious health problems.

Dive computers can handle each of those concerns for you, presenting the data clearly on a wrist or console-mounted unit. Basic dive computers are simple devices that measure conventional metrics and environmental conditions, while others such as our top pick, the Garmin Descent Mk1, offer a wider range of sensors, customization features, and multisport capabilities.

Considerations when choosing dive computers

Before we delve into the features and capabilities of dive watches, there are crucial elements to keep in mind that greatly affect their basic performance. The two biggest are battery life and depth rating, as they dictate how long and how deep you can dive. Battery life is particularly crucial, because if yours runs out of energy at depth, it literally becomes a life-and-death issue. Typical batteries last between 20 and 40 hours.

Depth ratings are dependent on the quality of build materials used, specifically the bezels and waterproof seals. The International Standards Organization dictates that for a product to be called a dive watch, it must be "designed to withstand diving in water at depths of at least 100 meters" (300 feet). There are computers capable of going much lower, however.

Features and prices

Nearly every dive computer will measure depth, time, and temperature, but units in the $200-plus-range separate themselves with a variety of dive modes. These can range from automatic modes that calculate no-decompression limits -- the amount of time you can safely stay at a given depth -- in real time, to gauge modes, to modes for specific equipment such as closed-circuit rebreathers.

Another distinction is the support of different gas types. Entry-level computers may work solely with basic enriched-air nitrox gas you find in every dive group, while others support compounds such as trimix, which combines nitrogen, helium, and oxygen for higher performance at low depths. These mixtures require special training to use, and appropriate dive computers can cost $800 or more.

Finally, dive watches with smart alarms and reminders separate themselves from the pack. These alarms include maximum depth, no-decompression limits, safety stops, gas levels, battery levels, rapid ascents, and the like. You'll have to shell out more money for a full-fledged alert system, but even affordable models equip depth and rapid-ascent alerts.


Q. Can a dive computer help me prevent decompression sickness?

A. Yes! Decompression sickness, also known as the bends, occurs when you dive deep and then surface too quickly. At depth, the pressure around you increases, and your body absorbs more nitrogen because of it. If you don't allow your body to off-gas by stopping occasionally, the nitrogen creates bubbles in your tissues that cause a variety of problems. Dive computers program safety stops into your routine with clever alarms, and are able to calculate how long you can safely stay at a given depth.

Q. What other diving equipment do I need to round out my setup?

A. A dive computer allows you to take the step from casual underwater adventurer to full-on aquatic explorer, but there are basic tools you need first. Fins, a mask, a regulator, and an exposure suit are standard diving tools, but items such as cameras, lights, knives, surface buoys, and defoggers can take your experience to the next level.

Dive computers we recommend

Best of the best: Garmin Descent Mk1

Our take: The Garmin Descent Mk1 is a true flagship, with a legion of sensors, diving modes, and advanced features at your disposal.

What we like: This watch-style computer includes nearly everything you need when diving deep. It's equipped with a three-axis compass, gyroscope, and barometric altimeter, and it supports several gas times. Experienced users will enjoy data storage for up to 200 dives, as well as the built-in heart rate sensor and performance metrics. Battery life is 40 hours in dive mode.

What we dislike: Some users found the customization options lacking for the price.

Best bang for your buck: Mares Puck Pro

Our take: So much more than a budget watch, the Mares Puck Pro offers an impressive feature set at a great value.

What we like: A slim, simplified interface that's easy to understand. Despite the low price, it's able to log 36 hours of dives, and it equipped with ascent rate indicators to prevent decompression. Features an automatic dive mode, a log mode to analyze records, and a planner to discern how long you can stay at a particular depth. The face is large and very easy to read at depth.

What we dislike: Does not have a depth alarm. 

Choice 3: Cressi Leonardo

Our take: With its large screen and intuitive operation, this dive watch is perfect for beginners.

What we like: Cressi's Leonardo dive computer is very easy to learn with a single-button interface. It tracks depth, dive time, ascension rate, and decompression time. Versatility is another high point, as this watch features air, nitrox, and gauge modes. Visual and audible alarms can be tailored for personal preference. 

What we dislike: The ascent alarm is too sensitive, as it can be triggered with quick movements. 

Andrew Hard is a writer for BestReviews. BestReviews is a product review company with a singular mission: to help simplify your purchasing decisions and save you time and money. BestReviews never accepts free products from manufacturers and purchases every product it reviews with its own funds.

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