Professional underwater photographer Jenny Stock tries out the merits of wireless air integration using the Suunto Tank POD
By Jenny Stock
I couldn’t be happier with the Suunto Ocean Dive Computer that I reviewed back in January, so I was eager to try the Tank POD that pairs with it.
First of all – what does it do? The Tank POD is a wireless air integration transmitter that connects to your regulator’s first-stage high-pressure (HP) port and enables you to view your tank pressure with a glance at your computer.
Being able to see how much air you have left in your tank without picking up your gauge is especially useful when you have your hands full underwater, which – as a professional underwater photographer – I always do!
Getting started
The Tank POD is 80 mm (3.15″) long, and weighs just 95g (3.4 oz), and can be attached to the first stage via two methods – either screwing it directly into the HP port where it sticks out on top at a right angle, or using a high-pressure hose extension.
Attaching your transmitter directly to your first stage might seem like the simplest option. However, the bulk of your other connecting hoses may get in the way, especially if the ports on your first stage are close together.
Attaching the POD directly to the first stage also means that overly-helpful dive staff might mistake it for a tank valve handle and grab hold of it when moving your kit, which might damage or snap the connector.
The risk can be reduced by mounting the transmitter on a high-pressure hose, which can have a secondary effect of improving the connection between POD and computer by bringing the two closer together (as long as it’s mounted on the same side of your body that you wear your computer). Suunto sells a short HP hose designed exactly for this purpose.
Both methods require the easy installation of a flow restrictor into the POD’s opening, which prevents an uncontrolled free-flow in the event of equipment malfunction. Flow restrictors for both methods of mounting are supplied on purchase.
The working range of the POD is 1.8 meters (6ft), and multiple PODs can be monitored during a dive, depending on the model of computer you are using.
The Suunto Nautic and Suunto Ocean can connect to up to five Suunto Tank PODs, thus enabling you to monitor the volume of gas in up to five cylinders during a dive – although you can only see the stats for one tank at a time. PODs are also compatible with the Suunto EON Core and EON Steel/EON Steel Black, which can monitor up to 20 tanks(!) and the older Sunnto D5, which can manage three.
Hypothetically, you could keep an eye on your buddy’s gas consumption if you were close enough during a dive and paired with their transmitter, but it is important to make sure that you are reading your own tank pressures, which are identifiable in the computer menu through the serial number which is unique to each POD.
Using the POD
I mounted my Tank POD to my first stage via a small high-pressure hose, and input the tank size (12 litres) into my Suunto Ocean dive computer menu.
The POD itself is only measuring volume of gas, so I select the gas I am using (Nitrox) on my Suunto Ocean computer and open the valve on my tank.
A green light begins to glow, which indicates my Tank POD is active. Synchronisation is automatic, but another option would be to connect via my computer’s menus.
Once connected, I have an accurate gas pressure reading. I also have a clear, colour-coded, graphic arch indication of my gas level. A full tank is blue, then dips to amber at 80 bar (1000 psi) as ‘cautionary’, then becomes red as a warning when my tank drops to 50 bar (725 psi) or below.
I also have a remaining gas time reading, which shows me how long my supply is expected to last at my current depth.
Time, gas volume and no-decompression limit (NDL) alarms can be set with warnings of audible bleeps or haptic vibrations. While diving in Turks and Caicos, I found a couple of alarms useful when using my POD. We were on a strict schedule to cram in five dives a day, so an alarm at 55 minutes told me it was time to leave the fish.
A pre-set gas volume alarm at 50 bar (750 psi) allowed me to plan a safe ascent with safety stop, and I set a vibration (no sound) alarm at 130 bar. As I was enjoying some fabulous wall diving, this let me know I was halfway through my dive, and it was roughly time for me to turn around and begin my saunter back to the boat.
During my dives, I could glance down at my wrist to see my air rather than reach around my bulky camera for my submersible pressure gauge (SPG).
The alarms gave me a pointed reminder when I was so preoccupied by my photography that I am human, and not a fish, so sadly, I needed to surface. After diving, my remaining gas volume was digitally logged, along with all my usual dive data, into my Suunto app. I love tracking this data – aside from my photos, viewing this is another way to relive the dive!
Some people dive with just a transmitter, however, it’s widely accepted that best practice is to use a backup analogue SPG when possible (assuming your regulator’s first stage has two HP ports).
The Tank POD’s battery life will keep it going for plenty of dives; batteries must be changed by an authorised Suunto Service Centre after two years or 200 dives, whichever comes first.
Overall, I found the Suunto Tank POD was a very convenient addition to my setup, allowing me to focus more directly on my activity, yet reminding me when I needed to take action for safety on a dive.
MSRP Suunto Tank POD: £320.00*
(*price may be lower when purchased with a compatible computer)
