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Aeris A300 Brings Balance To Recreational & Tech Diving

Aeris A300 Brings Balance To Recreational & Tech Diving

Aeris A300 is an advanced dive computer with Dual Algorithm, 4 dive modes, and possibility of setting up to 3 Nitrox mixes with FO2 up to 100%. Perfect as for beginners and recreational, and for technical divers too, since has few functions that will satisfy their demands completely.

General Information
User Interface
Your Review



Aeris A300 is an advanced dive computer with Dual Algorithm, 4 dive modes, and possibility of setting up to 3 Nitrox mixes with FO2 up to 100%. This instrument came with interesting characteristic - diver can choose between NORM (Air, Nitrox) and TECH modes. The latter characterized with better flexibility in adjustments and possibility to set 3 Nitrox mixes, while NORM mode has simplified number of functions just to cover our recreational diving needs.

It can be recommended dive computer for both beginners in diving and advanced recreational divers who want to be extra-challenged!


Aeris A300 Features Card

Copy this Aeris A300 Features & Alarms Card for your Reference and Share with your friends and buddies!


No matter that Aeris A300 is an advanced instrument - it is very easy to learn, set up and use. We can build a console on the base of this Aeris dive computer by adding submersible pressure gauge and compass to make fully featured NAVCON Aeris A300XT. As this dive computer has Dual Algorithm, someone may want to use it as a backup device for other Aeris, Oceanic, or even Tusa brands.



Benefits of using Aeris A300 dive computer

  • with intuitive and friendly user interface, and well-structured manuals you will learn quickly this advanced dive computer and get new skills with confidence;
  • you will be able to grow into this dive computer and dive recreational and technical scenarios;
  • you can start diving right away by setting its basic parameters - no high-tech skills required;
  • advanced safety functions allow you diving in wide conditions;
  • you will be able to replace battery yourself without losing dive data with Aeris A300's data retention feature;
  • if you want to expand its functions - dive computer's configuration allows to build a console by adding SPG and compass








User Interface
3 buttons
Dive Modes
Air, Nitrox, Gauge, FREEdive
Integrated Digital Compass
Dual: Pelagic DSAT & Z+
Number of Gas Mixes
3 (available in TECH mode only, in NORM mode - only 1 Nitrox mix)
Air, 21% - 100%
1.0 - 1.6 ATA
Air Integration
Safety Stop (SS)
Deep Stop (DS)
ON/OFF (available in TECH mode only)
Conservative Factor
ON/OFF (available in TECH mode only)
Altitude adjustment
Gas Switching
yes (available in TECH mode only)
Dive Planner
9 - 57 meters
Logbook Capacity
24 most recent dives
Max Operational Depth
120 meters
Backlight duration
5/10/15 sec
Sampling Rate
2/15/30/60 sec
User Replaceable Battery
Data Retention
PC Interface
2 years











Aeris A300 has 3 control buttons: MODE, SELECT, ADVANCE.

Dive computer has 2 coloured bar graphs - TLBG (nitrogen loading), which is located at the left side of display and VARI (variable ascent rate), which is located on the right side.
TLBG bar graph has 20 segments - 13 No-DECO conditions, 6 caution conditions, and the last top segment of TLBG represents DECO mode.
VARI bar graph - it's a visual indication of diver's ascent, and it will start flashing, if diver ascends faster than allowed.

A300 has several displays - main and alternatives, whether we are on surface or underwater. All information is presented in clear to understand format, and display layout is very intuitive.

User manual is structured well, so you won't find any trouble following it, even if it is your first dive computer. It was sent to us on CD, so if you sick of reading from PC - obviously, you'll need to print it out for your convenience! And that was the only discomfort, which we found when learning and diving with Aeris A300!







Aeris A300 is configured with several menus to make its setting process easier and more intuitive. And saying precisely - 5 menus:

  1. Set OP MOD;
  2. Set GAS;
  3. Set ALM;
  4. Set UTL;
  5. Set TME


User documentation is structured very well, so it is easy to understand. And by following that menu we may set next number of parameters:

  2. Set GAS: number of gases (up to 3 in TECH mode); FO2 - Air, 21-100%;
  3. Set PO2 - 1.0-1.6 ATA (in TECH mode);
  4. Set ALM:
    • audible - ON/OFF;
    • Depth alarm - ON/OFF/10-100 meters;
    • Elapsed Dive Time (EDT) alarm - ON/OFF/10-180 min;
    • TLBG alarm (TECH mode only) - ON/OFF/from 14 to 19 segments;
    • Dive Time Remaining (DTR) alarm (TECH mode only) - ON/OFF/5-20 min;
  5. Set UTL:
    • water type (TECH mode only) - fresh/sea;
    • units;
    • Deep Stop (DS) (TECH mode only) - ON/OFF;
    • Safety Stop (SS) (NORM mode) - OFF/ON/Timer;
    • Safety Stop (SS) (TECH mode) - OFF/ON/Depth/Timer;
    • Algorithm: DSAT/Z+;
    • Conservative Factor (TECH mode only) - ON/OFF;
    • backlight duration (TECH mode only) - 5/10/15 sec;
    • sampling rate - 2/15/30/60 sec
  6. Set TME:
    • hour & date formats;
    • time & date


Aeris A300 has RESET function that allows the diver to clear nitrogen memory. This feature can be a great benefit for dive shops, which give the dive gear for rent.

By using inbuilt Dive Planner we may plan next dives and dive computer calculates the NDLs according our nitrogen loading from previous dives, FO2 set point and Algorithm selected.







Aeris A300: Diving With Air & Nitrox

Aeris A300 turn on selected dive mode when senses depth about 1.5 meters.

As a dive computer, Aeris A300 operates in 4 modes:

  1. NORM – when you set it for Air or Nitrox with 1 gas mix;
  2. TECH - diving with up to 3 Nitrox mixes;
  3. GAUGE – in this mode A300 functions as a depth gauge and timer only and doesn’t perform calculations for nitrogen absorption and oxygen accumulation;
  4. FREEdive – this mode is for diving without scuba gear


For each dive mode this dive computer has main and alternative displays to show you all related data to any situation. To swap between them you need to press A-button for less than 2 seconds.

For SmartGlo activation - press S-button (the same button you will use to acknowledge alarms), and as this dive computer has Gas Switching option – M-button is designed to access Gas Switching function.


Aeris A300 Wrist NO-DECO card

Copy this Aeris A300 NO-DECO Displays Card for your Reference and Share with your friends and buddies!


In No-Decompression Mode you may have Deep Stop prompt if Deep Stop option was set to ON before. In this case Aeris A300 will display values related to Deep Stop function, like Stop Depth and Time, and Stop icon (bar and arrows).

If you set Safety Stop function to ON – dive computer will prompt you by beeping and displaying attributes for Safety Stop, like Safety Stop icon (bar and arrows), Stop Depth and Time counting down.

Deep and Safety stops have main and alternative displays, which diver may access by pressing A-button.


Dive computer constantly monitors our levels of PO2 and O2. And if certain conditions do exist - A300 switch on specific alarm with according display.

During the dive you may exceed No-Decompression time and depth limits. In this case instrument will activate Decompression Mode – audio alarm will come up and all segments on TLBG, UP Arrow icon and alarm LED will flash.


After having that, you need to ascend safely to the required depth, shown on the display, or a bit deeper, and stay at that depth required time that is shown as well. When you complete required Decompression time, next shallower Stop Depth will be displayed and you may ascend to that level to continue decompression process, and so on.

To assist us completing decompression correctly, Aeris A300 has main and alternative displays (4 of them all together) with all information we need. Below you may see the summary of Decompression Stop main and alternative displays:

  • current depth;
  • Total Ascent Time (TAT);
  • DECO Stop Depth and Time;
  • DECO Stop icon (bar and arrows);
  • full TLBG;
  • Elapsed Dive Time (EDT);
  • current PO2;
  • FO2 set point;
  • max depth;
  • time;
  • temperature;
  • applicable icons


It happens sometimes when you may create violations during Decompression Mode, like Conditional Violation, for example. It means that you ascended to shallower depth than required for Decompression Stop and maybe stayed at that shallower depth for a while. In that case you won’t get any off-gassing credits but instead you will receive a penalty time that must be worked off before, actually, off-gassing credit may be acquired.

To help us out in violation situation Aeris A300 has specific displays with information listed below:

  • current depth;
  • full TLBG;
  • required Stop Depth and Time;
  • Stop Bar and Down Arrow – to manage your ascent and descent;
  • applicable icons


When you descend to required Decompression Stop Depth and stay within stop zone – you will get full solid Stop icon (Stop Bar and Down/Up Arrows).

Other DECO violations include:

  1. Delayed Violation 1 (DV 1);
  2. Delayed Violation 2 (DV 2);
  3. Delayed Violation 3 (DV 3);
  4. Violation GAUGE Mode (VGM)


During single dive (in TECH mode only) you may switch gas mixes easily in appropriate moment. Aeris A300 gave me an alarm with preview display. By using A and M buttons to walk through the gas menu, and using S-button, I selected required gas, and all calculations started for that mix. It was easy and intuitive!


Aeris A300: Diving In GAUGE Mode

If Aeris A300 dive computer was set for GAUGE Mode, it will work as a depth gauge and timer and won’t calculate nitrogen and oxygen accumulation.

Below is an example of the displayed information from main and alternative screens when diving in Gauge Mode (to access alternative displays – press shortly A-button):

  • current depth;
  • max depth;
  • Elapsed Dive Time (EDT);
  • VARI when you ascend;
  • time;
  • temperature


If you want to interchange Elapsed Dive Time with Run Timer - press M-button.


Aeris A300: FREEdiving

You may use Aeris A300 dive computer for freediving, because it has set of special alarms and features to assist you during freediving. When set for FREEdive mode, instrument calculates your nitrogen and oxygen exposure that you may have from previous dives, and those figures are based on selected algorithm and FO2 for Air.

To use this dive computer for freediving you need to set FREEdive Mode and access and customize special functions available for freediving activities, like Countdown Timer (CDT), Freedive Elapsed Dive Time (EDT) alarm and Freedive Depths alarms.


Countdown Timer (CDT) may be set and toggled between ON/OFF. During freedive you may easily view CDT status on the alternative display and then Start it or Stop it.

Freedive Elapsed Dive Time (EDT) alarm is different thing from Elapsed Dive Time (EDT) alarm as you set it previously for NORM/TECH modes.
It is factory preset for 30 seconds and you may toggle it ON/OFF. This means that every 30 seconds of your time underwater you will hear audio comes up to remind you that another 30 seconds of freedive have gone.


Also Aeris A300 allows us to set 3 Free Depth alarms, each at progressively deeper depths. Set points are in a range from 10 meters to 100 meters (30 ft – 330 ft).
So, when you reach certain depth that was set – you will hear an audio signal and depth value will be showed up on the display.

Below is a summary of dive data that you will get during freedive from main and alternative (3 displays all together) displays (to swap between main and alternative displays – press A-button shortly):

  • current depth;
  • temperature;
  • Dive Time Remaining (DTR);
  • Elapsed Dive Time (EDT);
  • TLBG;
  • applicable icons;
  • Countdown Timer (CDT) status;
  • max depth reached;
  • time


Also, each Freediving alarm, which we set previously, will give us its specific type of display with all related information.

If you have High Nitrogen alarm during freedive - 14 segments of TLBG will flash with audio alarm. If level of nitrogen increases to DECO condition - dive computer will display full TLBG with audio, and graphics UP and VIO flashing. When you resurface - Aeris A300 scuba dive computer will lock itself to Violation Gauge Mode (VGM) for 24 hours, meaning that you need to stay out of any sort of diving.

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After the Transition Period you will have access to following modes of this Aeris dive computer:

  1. Plan Mode (NORM, TECH) – this function shows you for how long you may stay underwater safely and at what depth, according to your current nitrogen or oxygen accumulation, Algorithm selected, settings of Personal Conservative Factor and FO2 for gas 1 only;
  2. Set menus;
  3. No-Fly Countdown Timer;
  4. Desaturation Countdown Timer;
  5. Log Mode (NORM, TECH, and GAUGE modes) – it stores data of your 24 most recent dives (battery removal does not make any affect on Log memory);
  6. History Mode (NORM, TECH, and GAUGE modes) – accumulates information, like number of dives, number of dive hours, and max depth achieved from all your previous dives, lowest temperature recorded, etc. (battery removal does not make any affect on History memory);
  7. PC interface – this function allows you to upload and download data from Aeris A300 to PC by using special cable and software;
  8. NORM/TECH Clear – this feature allows you to clear nitrogen and oxygen memory – great beneficial feature if you use A300 for rental and training purposes







Aeris A300: What Divers say


  • convenient Dual Algorithm;
  • easy to read display at any conditions, large digits;
  • very easy to set up and use;
  • quick to set up for basic or tech diving;
  • user replaceable battery;
  • can be built to console versions


Aeris A300 is an advanced dive computer that allows user highly customize it for specific diving scenarios and dive technical, or quickly set it to basic recreational diving.

During our test dives we found it very reliable, accurate, and easy to use. Display was easy to read, audio alarms were loud enough and visual alarms were great help.
Gas switching didn't give us any troubles - easy button sequence did it smoothly!

User manual is well-structured, and it was easy learn and follow.


Aeris A300 Wrist dive computerAeris A300 Wrist

Dive-Computer-Wizard Rating
golden star golden star golden star golden star golden star


You may definitely invest in Aeris A300 as it can be recommended dive computer for recreational and technical diving. You will find it accurate, reliable, and user-friendly with variety of functions that may have other dive computers with higher price. Dive computer will work well as a backup device and as a training platform, because its CLEAR nitrogen memory function. That's why dive shops may consider it as an instrument that is possible to give for rent and earn some money!



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Colin, 1 August 2014 12:47
Good Money Investment

Solid computer and good value for money. Aeris makes nice dive computers that are easy to set and dive! This is my first computer and I'm very happy with it after 25 dives logged.
Maybe I'm not experienced yet to appreciate the difference between Aeris A300 and a $1000 computer, but for my use, it is perfectly priced and gives me all the information I need. I would recommend it to anyone who dives recreational.

Alec, 14 July 2013 13:42
Great NAVCON Aeris A300 XT

I've bought recently Aeris A300 XT navigational console with pressure gauge after reading reviews on this portal. I'm using it on my weekends diving and logged 23 dives already. No any complaints with this instrument!

I like integrated dive computer's backlight and low pressure alarm with SPG. Large display shows all important dive info - all easy to read. Buttons work fine, everything was designed ergonomically perfect.

I definitely recommend Aeris A300 XT navigational console to every diver who needs air integration and doesn't mind to have it on hose. I'm very happy for my investment.

JoshD, 22 May 2013 07:38
Aeris A300 - Multifunctional And Easy To Dive With

I finally got my first dive computer and loved my new Aeris A300.

I started diving not long time ago and want to progress fast, so having multi-funtional device is very important. I like possibility to choose between NORM and TECH mode, where I can do more adjustments, or leave it as basic - it works as a foolproof thing!

Even I logged just 23 dives on Aeris A300 - I may recommend this dive computer to everyone, it has great price-specs ratio!

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