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Tusa IQ-650 Element - Basic Dive Computer With All Functions to Run Air & Nitrox Dives With Ease

Tusa IQ-650 Element - Basic Dive Computer With All Functions to Run Air & Nitrox Dives With Ease

Tusa IQ - 650 Element is entry level dive computer that may be considered by newbies as their first dive instrument. 1 button easy access and retrieving dive data, Air and Nitrox dive modes, good manuals.

General Information
User Interface
Your Review



Tusa IQ-650 Element – it is recommended dive computer that may be considered by newbies as their first dive instrument or scubadiving clubs and scubadiving shops that may give it for rent, because IQ-650 has a Reset function.

This Tusa dive computer is easy to set and pretty straightforward to use and if you decide to get one – you won’t find any difficulties with it.

Tusa allows us to make 2 nice and handy versions of consoles with IQ–650. First one is SCA–251 with dive computer and pressure gauge and the second – SCA–351 with dive computer, pressure gauge, and a compass.


SCA-251 Console
SCA-251 Console: IQ-650 and Pressure Gauge
SCA-351 Console
SCA-351 Console: IQ-650, Pressure Gauge and Compass



Tusa Element IQ-650 console

Copy this Tusa IQ-650 Element Features & Alarms Card for your Reference and Share with your friends and buddies!


  • you will have basic dive computer with Nitrox capabilities that is easy to set up and use, and similar to Aeris XR1 NX, Oceanic VEO 100 NX, and Sherwood Profile;
  • you will be freed from adjusting many parameters to enjoy diving - some of them has automatic setup, some - are factory pre-set;
  • you may build air-pressure and Navigational consoles with Tusa Element IQ-650 dive computer;
  • you will be able to replace battery yourself and with battery 'hot swap' keep all settings safe;
  • you may save great amount of money on something esle if you prefer and invest in this simple dive computer;
  • you can use it as a main instrument or backup device








User Interface
1 button
Dive Modes
Air & Nitrox
Integrated Digital Compass
Buhlmann ZHL-16C
Number of Gas Mixes
Air, 21% - 100%
1.2 - 1.6 ATA
Air Integration
Safety Stop (SS)
Deep Stop (DS)
Conservative Factor
Altitude adjustment
Gas Switching
Dive Planner
9 - 57 meters
Logbook Capacity
12 most recent dives
Max Operational Depth
100 meters
Backlight duration
Sampling Rate
factory pre-set
User Replaceable Battery
Battery 'hot swap'
PC Interface
2 years










Tusa IQ-650 has only 1 control button for customization and retrieving all necessary data. And it is not very convenient without ‘step back’ function in user’s interface.

If you need to change some setting you did just before – you need to wait as sequence scroll it back to you. But, hey – it is a one button ‘puck’. They all have such kind of interface, so we don’t need to think about it as a disadvantage or something!

Dive computer has following bar graphs at our disposal:

  1. Nitrogen Loading Bar Graph (NiBG) – graphical representation of our nitrogen absorption. When we go deeper and stay longer – nitrogen level increases and when we ascend – nitrogen level decreases. And IQ-650 shows this on NiBG by adding or taking away segments. It has 3 zones – No-Deco, Caution (still No-Deco), and Decompression;
  2. Oxygen Bar Graph (O2BG) – shows us accumulated level of Oxygen during a dive or for a period of 24 hours;
  3. Ascent Rate Indicator (ASC) – shows us how fast or slow we ascend and shows corresponding number of segments


These bar graphs are quite similar to bar graphs in some Oceanic and Aeris dive computers.







There are not very many functions of Tusa IQ-650 to set and all process won’t take you long time at all.


Tusa Element IQ-650 Fine-Tuning Card

Copy this Tusa Element IQ-650 Fine-Tuning Card for your Reference and Share with your friends and buddies!


Also, like other dive computers, Tusa IQ-650 has Dive Planner. This function shows us No-Decompression times for depths at the range from 9 meters to 57 meters in 3 meters increments, depending on nitrogen and oxygen loading from the previous dives (if any).







Tusa IQ-650 Element: Diving With Air & Nitrox

Like other Tusa dive computers, IQ-650 has main and alternative displays that we my access during a dive. To swap them – that’s obvious – press the button.


Tusa Element IQ-650 NO-DECO Card

Copy this Tusa IQ-650 Element NO-DECO Displays Card for your Reference and Share with your friends and buddies!


Upon reaching certain conditions – Tusa IQ-650 may give us Deep Stop and Safety Stop displays with all corresponding attributes – depths and countdown timers, etc.

Difference between displays during diving with Air and Nitrox is such – in Air mode Tusa IQ–650 won’t show display with FO2 and PO2 values, and O2BG may not be seen as well if you dove only with Air previously.

When we exceeded our No-Decompression Limits (NDLs) – dive computer will activate Decompression mode. Display is easy to understand, so you won’t be confused. It will show following decompression data:

  • STOP notation and guiding arrows;
  • Decompression Stop depth and Decompression time;
  • Total Ascent Time (total time to surface);
  • applicable bar graphs and icons, etc.


During decompression stage you may have conditional violation (we will discuss only this one as an example) and this happens when you ascend above the displayed decompression stop depth by some reason (can be underwater current or rough seas, etc)

Tusa IQ-650 will warn you by flashing DOWN Arrow, Stop notation and Total Ascent Time. At this point we need to descend below displayed decompression stop depth before 5 minutes will finish to avoid further violations.

After we did that – off-gas credit starts working and after we have completed our decompression obligations successfully – dive computer turns to No-Decompression mode of operation.







Looks like we have made our underwater adventure with Tusa IQ–650 Element dive computer and it’s time to have a closer look at Log modes or plan our next dive with Dive Planner.

After the Transition period (10 minutes after dive) you may access following data and modes:

  1. No-Fly countdown timer;
  2. Desaturation countdown timer;
  3. Dive Planner;
  4. Logbook;
  5. Unit RESET







Tusa IQ-650 Element: What Divers Say


  • very easy to set and use;
  • one button for an easy access;
  • easy to follow documentation;
  • can be used in computer consoles versions...



  • no PC download option;
  • small logbook capacity...


After our review we may see that Tusa IQ-650 is very basic dive computer but still has all functions to manage safely diving with Air and Nitrox conditions.

Regardless of the fact that it is missing some desirable features like PC Interface and Gauge dive mode, Tusa IQ-650 is good choice for dive clubs and dive shops that may give this dive computer for rent or for your backup computer.


Tusa IQ-650 Element dive computer
Tusa IQ-650

Dive-Computer-Wizard Rating
golden star golden star golden star half star silver star


You may consider investing in Tusa IQ-650 Element if you want to have straightforward and reliable backup dive computer without going too deep into technical issues.



Add comment
Etsuko, 15 November 2013 12:22
Great For Backup

I'm using Tusa IQ-650 built in console SCA-351 as a backup dive computer for my Tusa IQ-900 Zen. It is very easy to set and operate with 1 button user interface. And with its 2 dive modes this dive computer is a complete solution as a backup for those who dives with other Tusa dive computers. It is very reliable and no problem with lacking of PC interface.

Ron, 14 May 2011 10:14
Tusa IQ-650 - The Easiest Dive Computer To Dive With

I have been diving with my Tusa IQ-650 for more than 2 years already. What to say about it? Reliable and the easiest dive computer I have ever used!

IQ-650 easy manages no-decompression dives and ascent speed, digits are quite big and display has good readability. I don't go for decompression dives very often, but if it happens - Tusa has everything I need for proper decompression and safe ascent.


Dive computer has only 1 button for access and retrieving information. Someone may say, that it is not very convenient user interface, which doesn't has "step back" function, but for me - the easier - the better.

Mainly it is my backup, because this computer doesn't have PC download option, audio alarms and backlight. I have it in a console with pressure gauge and it is very nice addition to my main dive computer Oceanic Geo 2.0.


They don't have too much difference in reading dive data, since Geo 2.0 has Dual Algorithm: Pelagic DSAT and Pelagic Z+ and may be set up for either conservative or liberal diving. Another good thing about this computer - diver replaceable battery and battery "hot swap" option. This procedure is very easy - it took me just once to follow instructions in user manual and now I do battery swap as a pro!

It is good, solid and reliable dive computer! If you need perfect backup instrument - think Tusa IQ-650!

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