Monday, 3 November 2008


The Apex Quantum Dive Computer retails at a bargain price of £150, but its no budget computer. It has certainly been a popular computer since its launch 4 years ago. If you are looking for a dive computer should you still seriously consider the Quantum?
So what do you get?
Firstly you get gas switching capability for up to two mixes. The first gas can be set from nitrox 21% to 50% the second gas can be set from 21% to 99%. I found this to be of great use whilst decompressing on a nitrox mix, it was easy to switch gas. A couple of points to note. - Gas 1 operates at a PO2 of 1.4 whilst mix 2 operates at a PO2 of 1.6. and the computer will not allow a change to gas 2 to occur where the PO2 of the mix is greater than 1.6. The Quantum unlike some other gas switching computers resets the nitrox mix to 21% at midnight each night. I think this is better than having the last nitrox mix remain, where the likelihood of a mix-up may be greater but remember to change the time on the computer if you dive abroad.
As said switching mixes is easy, this is due to 3 buttons, which enable you to navigate through all the computers functions. A large Mode button changes modes through Time, Dive, Plan, Log etc.
Two smaller side buttons start the backlight illumination and access sub menus when in surface mode.
Underwater the right hand button shows other information, which is not critical to the dive such as temperature etc.
The quantum also operates in gauge mode recording depth and time, which is excellent if you are using, tables for say trimix diving.
I found when diving with the unit that it was very clear to read, the screen was uncluttered but showed all the critical information that you require on a dive. Ascent rate, Oxygen level, and Nitrogen levels are all shown in nice bar graphs around the screen.
My first dive with the unit was in murky waters, at the caves in loch long and the unit was clear to read. A quick touch of the button and the screen is illuminated in a pale blue light that doesn’t destroy vision that has adjusted to dark conditions.
I tested the Quantum beside Suunto D9 and Uwatec Aladdin Pro Nitrox computers and found the Quantum gave very similar readings to the Suunto D9.
Things I didn’t like so much about the Quantum were basically the strap, which I had difficulty getting over my drysuit. The strap went on but only had 2 holes to spare making donning the unit a bit of a fiddle. The other thing I noted was that the plastic the unit is made of felt a bit light, dare I say a bit cheap. To test this I certainly put the unit through its paces and bar a few scratches on the casing the unit stood up to the rigors of Scottish diving with no problems at all.
A screen guard is available for the unit although I never tested it, but I always feel its wise to protect the screen of a computer. I did find that the screen of the Quantum is recessed so whilst I landed a few scratches on the case the face was protected and remained scratch free.
Another accessory for the Quantum is a PC interface. The Quantum has a good onboard memory for storing dives, depending on what sampling rate you set, it will be between 30 and 60 dives, so there is no worries about dive information being overwritten if you are away on a week long trip. I used the PC interface and found it a nice tool, the software providing all the information about my dives. It also provides the facility for creating a logbook for your dives. I found it easy to use and although it’s not an absolute necessity it is a nice piece of kit to manage all your diving info.
My conclusion then is even before looking at the price this is a great computer, with all the functions most divers will ever require. It may not have luxury functions such as air integration but what you do get along with its easy read screen and clearly set out manual is a very competent and easy to use dive computer. Factor in the budget price and I think the Apex Quantum is one of the best Buy’s around today and for the foreseeable future.
Mike Clark