Easy to Use Budget Computer
AquaLung i300c

Described by Aqua Lung as having an uncomplicated, intuitive, and rugged design, the i300c is a great computer for anyone looking for an option that’s more versatile than an entry-level computer. With a great price point for the features it offers, the i300c has something for all divers. Offering gas switching, multiple dive modes, a user changeable battery, and Bluetooth connectivity, this computer certainly packs a punch in terms of features.

Want to get your hands on the Aqua Lung i300c? Click on the link above for the latest prices and details or read on for our full review.

Our Overall Review


Things we like:

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    Bluetooth access to data and settings
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    The battery is easy to change
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    Multiple diving modes
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    Gas switching is possible
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    Automatic altitude adjustments

Things we don't like:

  • check-markThe screen is on the small side
  • check-markBoth of the i300c’s two buttons can be difficult to push with gloves on underwater

Where to buy:


AquaLung i300c

Which is Better, the Aqua Lung i300c or the Suunto Zoop Novo?

The original i300 was Aqua Lung’s first entry-level computer after the company ended its relationship with Suunto. However, with the i300c it has far surpassed the features of the Zoop Novo, and at a lower price too.

The i300c does have a slightly smaller screen, which isn’t dot matrix, making it slightly harder to read. It also has fewer buttons, which can make it more difficult to navigate through the various menu options. But both in looks and in terms of what’s under the hood (well under the screen), the i300c outperforms the Zoop Novo hands down.

While neither of the two computers is likely to be worn as anything other than dive computers, the i300c looks a bit more like a watch. The Zoop Novo, with its bright colors and the huge display, looks very obviously like a dive computer. The average diver (unless they’re very proud of their new toy) is unlikely to wear it out for a post-dive beverage. The i300c on the other hand, while still on the chunky side, wouldn’t look out of place as a sports watch.

With its use of a Buhlmann based, rather than an RGBM decompression model, the i300c is likelier to appeal to divers with some experience. We’ll talk about decompression models and what this means for the diver in a bit.

When it comes to providing information to recreational divers about how close they are to their no decompression limit (NDL) the i300c certainly provides far greater options that the Zoop Novo. For example, the Zoop Novo only provides the diver with the number of minutes remaining before they reach the limit.

The i300c, on the other hand, also gives divers a visual graph on the left-hand side of the screen. This graph indicates how close the nitrogen compartment currently in charge of the dive is to saturation. As divers ascend and different tissues take over, the graph also displays a visual representation of how long the NDL is extended by.

The fact the i300c is also completely controllable, either manually or via Bluetooth connectivity, is a serious advantage.

While both are designed to appeal to entry-level divers, the i300c has more features and is capable of keeping up with the needs of a demanding recreational diver.

Specs & Features

  • Backlit
  • Depth rated to 100m/330 ft
  • EANx compatible, 21% to 100%
  • Multiple gas switches (up to three tanks, air and Nitrox only)
  • ppO2 settings from 1.1 to 1.6
  • Audible alarms
  • Dedicated freedive mode
  • Optional deep stops
  • Logbook and history mode
  • Bluetooth technology
  • Two-button menu navigation
  • Salinity adjustment
  • Conservatism factor adjustments
  • Wrist and console options
  • Automatic altitude adjustments
  • Plan mode
  • User changeable battery
See the complete list of the best Dive Computer here!

What You Need to Know About the Aqua Lung i300c

After taking the Aqua Lung i300c for a test dive, these are the features we noticed.

Bluetooth Connectivity

The DiverLog+ app (available for both iOS and Android devices) allows the diver to transfer all their dive data to their mobile or tablet. Divers can also change all settings on the computer using an app, rather than having to navigate the various menus on the computer itself. Given that we’re in the 21st century and there is an app for everything, it makes perfect sense that divers should be able to do a quick check of their dive computer settings on a smartphone or tablet without having to scroll through endless menus.

The app itself has optional social media integration so divers can share depths, times, and images from the dive with their nearest and dearest, or people they’d like to make jealous! You can find more info on the app here.

Four Operating Modes

The Aqua Lung i300c allows divers to select between four different modes: air, Nitrox (with gas switching and up to 100% oxygen), gauge mode, and freedive mode.

In air mode, the i300c provides information on NDL, dive time, current depth, ascent speed, N2 levels, and water temperature, among other things. In Nitrox mode, the i300c shows divers the information normally provided in air mode and provides information on the ppO2 as well as providing the diver with a variety of alarms should any of these settings be violated.

While the i300c allows for a diver to switch between a maximum of three gas mixes during a dive (including 100% oxygen), the instruction manual expressly states that it should not be used for planning or running a decompression dive. Should a diver try to use the computer for decompression diving, the algorithm will try to bring the diver safely to the surface.

However, in situations where the computer cannot accurately plan a safe ascent, it defaults to what Aqua Lung refers to as “Violation Gauge Mode.” This means the computer will stop trying to calculate safe ascents and solely provide information on current depth and time.

That said, should anyone wish to use the i300c as a backup for decompression diving, it does provide a gauge mode. In this mode, the computer is a bottom timer only and records depth and dive time without calculating NDL or providing any further information on the dive.

One useful feature of the gauge mode it that it provides to-the-second information for dives of no longer than 59 minutes and 59 seconds. After that point, it just displays run times in whole minutes.

Since the i300c is depth rated to 100m/328ft, the computer is a good option for divers who do a mix of recreational and technical diving and prefer not to use their tech computer on all their dives.

In freedive mode, the computer allows the diver to set multiple alarms which inform the diver of their countdown time, dive time, depth and whether they are reaching high nitrogen levels.

User Changeable Battery

Users can change the Aqua Lung i300c’s battery at home and it retains data about previous dives. The box even includes the tool needed to safely open the computer. This is an excellent feature for divers who frequently explore in remote areas or places where it’s hard to get the computer to a service center.

Automatic Altitude Adjustments

We have to hand it to Aqua Lung here, the i300c is the only entry-level computer we’ve reviewed recently that has this feature. On the Suunto Zoop Novo, for example, divers have to choose between three altitude ranges. The i300c can account for the exact height above sea level and adjusts the algorithm accordingly. We think this is ideal for people who frequently dive at altitude.

User Downloadable Software

Unlike other manufacturers, Aqua Lung allows i300c users to update the software on their computers independently. While the downside is the data cable, which has to be purchased separately, it does mean users can keep up to date with new releases without having to send the computer away for servicing.


Related Reviews

The Aqua Lung i300c’s Decompression Model

The i300c uses a version of Buhlmann’s ZHL-16c as its decompression model.

The basis of all decompression theory is that nitrogen bubbles form in body tissues during a dive. As divers ascend, these bubbles need to be expelled from the body otherwise they grow too large and can cause decompression sickness (DCS). The various tissues in the body absorb and release nitrogen at varying speeds and these need to be accounted for while planning a dive as the deeper and/ or longer a dive, the more bubbles a diver accumulates.

The father of decompression theory, John Haldane, observed that DCS symptoms did not present if decompression ceilings were limited to half the previous ambient pressure. This lead to his development of schedules for five tissue compartments, where when the pressure is changed the half life of the compartment would see it gain or lose one half of the inert gas it could gain at the current pressure.

In the 1960s, Swiss physicist Dr AA Buhlmann developed Haldane’s theories further and argued that there were actually 16 tissue compartments that would on and off gas and determined a divers risk of developing DCS. These compartments have a half time ranging from 4 minutes to 640 minutes.

What Does This Mean for the Diver?

In practical terms what this means is that there is a constant switch between which compartment is “running” the dive, do we need to watch the faster tissues at this depth or the slower one? How much time do the slower tissues require in order to off gas vs how quickly are the faster tissues on gassing? Using the N2 graph on the i300c, the diver has a visual representation of whether tissues are reaching critical saturation points.

Various conservative factors can also be added to the dive to ensure that it is conducted as safely as possible. These conservative factors calculate NDL on the assumption that the dive is taking place at the next higher 915 meter (3,000 foot) altitude. At sea level, calculations are based upon an altitude of 1828.8 m (6,000 feet). Buhlmann’s table were some of the first and best to calculate diving changes to NDL based on diving at altitude, which requires special procedures due to the difference in pressures.

Buhlmann’s decompression model is probably one of the most respected in diving and frequently used by technical divers when planning their dives. This means, that used safely and within its limits, the model will keep you as safe as possible. While safety stops are still recommended (and the i300c will remind you to keep to them) it’s flexible and accurate algorithm will effectively calculate a safe dive for repetitive dives.


Aqua Lung’s After Sales and Servicing Support

As an international company, Aqua Lung has service centers all over the world. While the i300c has a two-year limited warranty from the point of purchase from an authorized Aqua Lung dealer, any claims relating to defects or failures must be submitted to that dealer first, with proof of purchase. If the local dealer is unable to resolve the issue, the item will then be sent back to Aqua Lung for evaluation and/or replacement.

Having dealt with Aqua Lung in the past, this reviewer knows the process can be more drawn out than with other companies.

Owners of a new i300c should register their dive computer here.

The Aqua Lung i300C Dive Computer & DiverLog+ App

Any Ongoing Maintenance?

As with any dive computer, the i300c should be thoroughly rinsed in clean, fresh water at the end of the diving day. It is a delicate piece of equipment and should be treated as such. Although Aqua Lung describes it as “rugged,” multiple hard knocks, drops, or other acts of carelessness will damage it. Aqua Lung suggests using the lens protector supplied with the computer to ensure the screen remains scratch-free.

The Aqua Lung i300c is perfect for any technologically savvy diver who wants to download their dive data and control the computer’s settings via mobile or tablet.

Running one of the best decompression algorithms out there, the i300c will keep you safe, and its information on nitrogen loading is second to none in its category. The casual diver can maintain the computer themselves thanks to its user changeable battery and downloadable software. While the more experienced diver may find it a little limiting, for someone who just wants something on their wrist or console to keep them safe the i300c is perfect.

The Aqua Lung i300c is an excellent entry-level computer packed with some serious features. We like that it’s got the capabilities to support demanding recreational divers, too. Looking for the key takeaways from our review? You’ll find those below.

Our Overall Review


Things we like:

  • check-mark
    Bluetooth access to data and settings
  • check-mark
    The battery is easy to change
  • check-mark
    Multiple diving modes
  • check-mark
    Gas switching is possible
  • check-mark
    Automatic altitude adjustments

Things we don't like:

  • check-markThe screen is on the small side
  • check-markBoth of the i300c’s two buttons can be difficult to push with gloves on underwater

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