Aqualung i300C Wrist Dive Computer

Aqualung i300C Wrist Computer: A No-Fuss Recreational Dive Computer with Wireless Logging

The Aqualung i300C is a wrist-worn dive computer aimed squarely at recreational divers who want reliable, readable data underwater without wrestling with a complicated menu system.

If you are newly certified or a few years into recreational diving and shopping for your first personal computer, the i300C is worth a serious look. It covers everything a recreational diver needs day-to-day, and it adds Bluetooth connectivity for effortless dive logging, which puts it a step ahead of the basic entry-level options.

Four Modes That Grow With You

The i300C runs four operating modes, and the one you use will depend on what you are doing that day:

• Air tracks your no-decompression limits (the time you can stay at depth before a safety stop becomes mandatory) on a standard air fill.
• Nitrox supports up to three gas mixes with up to 100% oxygen, so if you pick up your Enriched Air certification down the road, the computer is already ready.
• Gauge turns the i300C into a depth gauge and bottom timer with a run timer, useful when you want to follow a divemaster's lead rather than your own computer profile.
• Free Dive tracks your breath-hold sessions and, importantly, keeps its calculations running so you can switch between scuba and freediving on the same day without the computer losing its place.

That last point matters more than it sounds. Some entry-level computers treat a mode switch as a full reset. The i300C does not, which makes it genuinely useful for divers who mix both disciplines in a single day at the pool or on a boat trip.

The Algorithm Behind Your Safety

The i300C uses a Buhlmann ZHL-16C based PZ+ algorithm to calculate your no-decompression limits. Buhlmann ZHL-16C is a well-established, widely trusted model that tracks how nitrogen absorbs into and releases from your body tissues at depth. The PZ+ layer is Aqualung's own refinement on top of that foundation.

You also get an optional deep stop with a countdown timer. A deep stop is a brief pause at depth, typically around the midpoint of your ascent, that some divers add as an extra precaution. It is optional here, so you can enable or ignore it based on your training and preference.

The computer is altitude adjustable up to 14,000 feet (4,270 meters) and lets you select salt or fresh water. Both adjustments affect how the algorithm calculates your limits, and having automatic altitude adjustment means the i300C recalibrates itself when you are diving a mountain lake rather than the ocean.

Reading It Underwater

The display reads depth to a maximum of 330 feet (100 meters), well beyond the recreational limit of 130 feet (40 meters), so you have headroom in the readout even if you never approach the deeper end.

A built-in backlight means low-visibility dives or night dives do not leave you squinting. Beyond the visual display, the i300C also has audible alarms and a high-visibility LED warning light, so critical alerts reach you through more than one channel if you are focused on something else underwater.

Starting a Dive and Checking Your History

The i300C uses a water-activated on switch. You enter the water and it turns itself on. There is no button sequence to remember when you are already kitted up on the back of a boat.

A single button press pulls up your last dive's maximum depth and bottom time. The history mode stores your last 24 dives along with total dive count, maximum depth ever recorded, total hours underwater, and lowest temperature logged. That is a useful snapshot for a recreational diver tracking their experience, though if you want a deeper log you will need to connect to the app or software.

Pre-Dive Planning

Before you get in the water, the i300C lets you run a pre-dive planning preview. You can check what your no-decompression limits will look like at a given depth before committing to the dive. For a recreational diver building good habits around dive planning, this is a practical tool to use alongside a surface interval.

Bluetooth Logging and Software

The C in i300C stands for the Bluetooth connectivity that separates this model from the standard i300. After a dive, you can wirelessly sync your log to the DiverLog app, which lets you review profiles, add notes and location details, and share content.

For more detailed control over computer settings and profile data on a computer, DiverLog software works on both Mac and PC. Note that DiverLog is sold separately through ediverlog.com, and if you want to update the computer's firmware or download via cable rather than Bluetooth, you also need to purchase the optional download cable (SKU: UDRPCI200) separately. Neither is included in the box.

Battery and Longevity

The i300C runs on a standard CR2450 3.0V lithium battery, which you can swap yourself without sending the computer anywhere for servicing. Critically, it retains all your settings and logged calculations through a battery change. You will not lose your dive history or have to reprogram your nitrox settings just because the battery ran out between trips.

What Comes in the Box

• Aqualung i300C wrist computer
• Digital instruction manual
• Safety reference information
• DiverLog brochure
• Quick reference card
• Lens protector
• Battery compartment opening tool

The download cable and DiverLog software are not included and must be purchased separately if you want wired connectivity or full desktop logging.

Who This Computer Is Not For

The i300C is not air-integrated, meaning it does not connect to a transmitter on your tank to show your remaining gas supply on the display. If you want cylinder pressure on your wrist, you will need to step up to a different model.

The 24-dive log is adequate for most recreational divers but may feel limiting if you dive frequently and want months of history on the device itself. In that case, regular Bluetooth syncing to the app becomes more important, not optional.

Technical divers or those pursuing decompression diving will also find the i300C underpowered. It is built for no-decompression recreational diving, and nothing about its feature set targets the technical end of the sport.

For a recreational diver who wants a clean, dependable wrist computer with wireless logging and room to add nitrox capability later, the i300C is a well-considered choice from a manufacturer with a long track record in dive equipment.