Seac Action Dive Computer
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Seac Action Dive Computer - Black is backordered and will ship as soon as it is back in stock.
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Product Information
The Seac ACTION is a wrist-mount dive computer for scuba and freediving that runs the Bühlmann ZHL-16C decompression algorithm in SCUBA mode, supports air, Nitrox, and mixes with oxygen concentrations up to 99%, and stores 40 hours of scuba logbook data sampled every 5 seconds. It also includes a GAUGE mode for simple depth and time tracking and a FREEDIVING mode for dive and surface time.
Who it is for
The Seac ACTION suits a diver who wants one wrist computer for recreational scuba diving on 1 or 2 gas mixes, occasional gauge-mode diving, and freediving sessions. SCUBA mode manages full dive profiles with the Bühlmann ZHL-16C algorithm, GAUGE mode gives an independent depth gauge and stopwatch, and FREEDIVING mode reports current and maximum depth along with dive and surface time.
Key details
- Decompression algorithm: Bühlmann ZHL-16C for 1 or 2 gas mixes (air, Nitrox, and mixes up to 99% O2).
- Logbook memory: 40 hours in SCUBA mode with records every 5 seconds, 18 hours in FREEDIVING mode with records every 2 seconds.
- Safety alarms: MOD exceeded, deco stop violated, ascent speed, NoFly time and desaturation calculations, and maximum permitted altitude warning.
- Dive planning: "NDL only" Dive Planner.
- Display: LCD screen with contrast and adjustable-intensity backlighting.
- Battery: CR2450.
- Data download: via USB cable, sold as an optional accessory, paired with Dive Manager software for Mac/PC (requires Windows 10), free at Seacsub.com.
Compatibility and sizing
The Seac ACTION is offered in Black, Black/Blue, and Black/White color options. It comes in two build configurations: the ACTION with a stainless steel crown, buttons, and buckle, and the ACTION HR with an HR-treated crown, buttons, and buckle for enhanced corrosion resistance. Both configurations use the same Dive Manager software for log download via the optional USB cable.
DiveCatalog.com is an authorized Seac dealer and a dive shop in Irvine, California, operating since 2003. Call or chat with us if you have questions about color options, ACTION versus ACTION HR, or software compatibility before you order.
- Three dive modes: SCUBA, GAUGE, and FREEDIVING are built into a single wrist computer.
- SCUBA mode algorithm: Bühlmann ZHL-16C decompression algorithm manages recreational dive profiles for 1 or 2 gas mixes, supporting air, Nitrox, and mixes with O2 concentrations up to 99%.
- GAUGE mode: Depth gauge and stopwatch for managing dive profiles independently.
- FREEDIVING mode: Reports dive and surface time along with current and maximum depth.
- Logbook memory: 40 hours in SCUBA mode with records every 5 seconds, and 18 hours in FREEDIVING mode with records every 2 seconds.
- Safety alarms: MOD exceeded alarm, deco stop violated alarm, ascent speed alarm, NoFly time and desaturation calculations, and maximum permitted altitude warning.
- Dive planner: "NDL only" Dive Planner for pre-dive planning.
- Display and power: LCD screen with contrast and adjustable-intensity backlighting, powered by a CR2450 battery.
- Data management: Dive Manager software for Mac/PC (requires Windows 10), free at Seacsub.com, with data downloadable via an optional USB cable.
- Durable structure: Treated for improved resistance to blows, corrosion, and swings in temperature.
- Two build configurations: ACTION with a stainless steel crown, buttons, and buckle, or ACTION HR with an HR-treated surface for enhanced corrosion resistance.
| Modes | SCUBA, GAUGE, FREEDIVING |
| Decompression algorithm | Bühlmann ZHL-16C |
| Gas mixes supported | Air, Nitrox, and mixes with O2 concentrations up to 99% |
| Number of gas mixes | 1 or 2 |
| Logbook memory, SCUBA mode | 40 hours, records every 5 seconds |
| Logbook memory, FREEDIVING mode | 18 hours, records every 2 seconds |
| Safety alarms | MOD exceeded, deco stop violated, ascent speed, NoFly time and desaturation, maximum permitted altitude |
| Dive planner | "NDL only" Dive Planner |
| Display | LCD with contrast and adjustable-intensity backlighting |
| Battery | CR2450 |
| Data download | USB cable (optional accessory) |
| Software | Dive Manager for Mac/PC, requires Windows 10, free at Seacsub.com |
| Materials, ACTION | Stainless steel crown, buttons, and buckle |
| Materials, ACTION HR | HR-treated crown, buttons, and buckle |
| Color options | Black, Black/Blue, Black/White |
⚠️ 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 Seac ACTION and Seac ACTION HR?
The ACTION has a stainless steel crown, buttons, and buckle, while the ACTION HR uses an HR-treated crown, buttons, and buckle for enhanced corrosion resistance. Both share the same SCUBA, GAUGE, and FREEDIVING modes, Bühlmann ZHL-16C algorithm, logbook memory, and CR2450 battery.
Does the Seac ACTION support Nitrox and other gas mixes?
Yes. In SCUBA mode the Seac ACTION uses the Bühlmann ZHL-16C algorithm and can manage air, Nitrox, or mixes with oxygen concentrations up to 99%, with support for tracking 1 or 2 gas mixes during a dive.
How do I download dive logs from the Seac ACTION?
Data transfers via a USB cable, which is sold as an optional accessory, into Dive Manager software for Mac or PC. The software requires Windows 10 and is available free of charge at Seacsub.com.
What does FREEDIVING mode show on the Seac ACTION?
FREEDIVING mode reports dive time and surface time along with current and maximum depth. It logs up to 18 hours of freediving activity with records taken every 2 seconds, separate from the 40-hour SCUBA mode logbook.




















