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Mares Dive Computer Sirius L Black

Mares  |  SKU: 414180BKBK
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Regular price $258.95
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Product Information

The Mares Sirius L is a lightweight, watch-style wrist dive computer that runs the Bühlmann ZH-L16C algorithm with adjustable gradient factors, handles nitrox from 21% to 99% with gas switching for up to three gases, and pairs with the Mares app over built-in Bluetooth. It is Mares' lighter-cased version of the Sirius, built around a clear LCD display and simple two-button navigation.

Who it is for

It suits recreational and nitrox divers who want one device for both the dive and daily wear. Air, Nitrox, Multigas Nitrox, Freedive and Bottom Timer modes cover single-gas recreational dives, decompression planning with multiple mixes, breath-hold sessions and gauge-only diving, while time, stopwatch and daily alarm functions keep it useful topside. Divers who travel will appreciate the user-replaceable CR2450 cell, which can be changed without sending the computer in for service.

Key details

  • Maximum displayed depth of 100 m / 328 ft, with an ascent rate indicator in m/min or ft/min.
  • Memory holds over 200 hours of dive profile at a 5-second sampling rate; logbook for up to 100 dives with graphs through the Mares app.
  • Safety Stop and Safety Stop+, the latter an optional extended stop with a countdown timer to encourage slower, lower-stress ascents.
  • Decompression dive planner with user-adjustable surface interval, plus selectable units, fresh or salt water, altitude adjustment and residual nitrogen reset.
  • CR2450 battery, user replaceable, with approximately 200 to 300 hours of diving per cell.

Compatibility and sizing

Bluetooth pairs the Sirius L with the Mares app to upload dives, manage the logbook and receive automatic firmware updates. The strap is easily replaceable with color straps or a bungee mount, both sold separately. This listing is the Black color option.

DiveCatalog.com is an authorized Mares dealer and a real dive shop in Irvine, California since 2003. Call 888-701-4017 or start a chat if you have questions about strap options, app setup or whether the Sirius L fits how you dive.

⚠️ WARNING: This product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.

Frequently Asked Questions

Why do I need my own dive computer?

A dive computer tracks the actual depth and time profile you have dived and the tissue loading that follows from it, which is personal to you. A rented computer has no record of your recent diving, and swapping models each trip means relearning the display and menus when you should be focused on the dive. Owning one you know well is a genuine safety and comfort improvement.

Can two divers share one dive computer?

No. A computer only tracks the profile of the diver actually wearing it, and even buddies who stay together do not follow identical depth and time profiles. Every diver needs their own computer, and passing one between divers or between dives is unsafe.

What does conservatism mean on a dive computer?

Conservatism settings make the computer's calculations more cautious, shortening allowed bottom times and adding margin beyond the base algorithm. Divers commonly add conservatism for factors such as cold, hard work, fatigue, or repetitive multi-day diving. How and when to adjust it is covered by your training and your computer's manual, so set it before you get in the water and follow what your computer tells you during the dive.

What kind of battery does a dive computer use?

Broadly there are two types: user-replaceable batteries, often a coin cell that you or a shop swap along with resealing an o-ring, and sealed rechargeable batteries that charge from a cable or dock. Neither is universally better, as replaceable cells are convenient on remote trips while rechargeables avoid ever opening the case. Follow the manual exactly for any battery change, because an improperly seated o-ring or case is the usual cause of a flooded computer.

Do I need to do anything special for altitude diving or flying after diving?

Yes, both change the picture, and both are governed by your training agency's guidance and your computer's instructions rather than any casual rule of thumb. Many computers have an altitude setting that must be configured before diving at elevation, and most display a no-fly or surface-interval countdown after a dive. Follow your computer and your training, and ask a dive professional or a dive-medicine specialist if you are unsure.

How do I care for a dive computer?

Rinse it in fresh water after every dive day, paying attention to the buttons and around any sensor openings where salt crystals form, and let it dry fully before storing. Keep it out of prolonged direct sun and extreme heat, and avoid pressing buttons while sand is on the case. Inspect the strap or bungee often, because a failed strap loses far more computers than a failed computer does.

What is the difference between wrist, console, and air-integrated dive computers?

A wrist computer is worn like a watch and read by raising your arm, while a console computer sits at the end of a hose with your other gauges. Air integration means the computer also displays cylinder pressure, either through a hose or from a wireless transmitter on the first stage, and often estimates remaining gas time. All of them run a decompression algorithm, so the real difference is where you read the information and how much of it you get.

What is the difference between the Mares Sirius L and the standard Sirius?

The Sirius L uses a lighter case than the standard Sirius, while keeping the watch-style format, LCD display and two-button navigation, along with the Buhlmann ZH-L16C algorithm, nitrox to 99%, multigas support for up to three mixes, built-in Bluetooth and a user-replaceable CR2450 battery. This listing is the Black color option.

Can I change the Mares Sirius L battery myself?

Yes. The Sirius L uses a CR2450 coin cell that is user replaceable, so you can change it without sending the computer out for professional service. A cell is rated for roughly 200 to 300 hours of diving. As with any user-serviceable dive computer, follow the manual's instructions for the o-ring and case seal when you swap the cell.

Does the Mares Sirius L work with a bungee mount?

Yes. The strap on the Sirius L is easily replaceable, so you can fit a bungee mount or one of the Mares color straps. Both are sold separately. Many divers choose a bungee mount when wearing thick exposure suits or drysuits.

How does Safety Stop+ work on the Sirius L?

Safety Stop+ is an optional extended safety stop with a countdown timer, offered alongside the standard Safety Stop. It encourages a longer pause in the shallows to reduce decompression stress and promote safer ascents. You enable it in the computer's settings, and the display then counts the stop down for you at the end of the dive.

Review summary

4.8 29 ratings across the web

The Mares Sirius L is a wrist dive computer in a lighter case than the standard Sirius. It handles nitrox from 21% to 99% with gas switching during the dive, displays depth to 100 m / 328 ft, and shows ascent rate in metres or feet per minute. Memory holds over 200 hours of profile at 5-second sampling, and it has watch, stopwatch, alarm, and plan modes. The CR2450 battery is user replaceable. Written reviews are still few. It suits divers who want a configurable nitrox computer in a smaller case.