The other day I was chatting with a friend who said his favourite watch was the S-brand because you can stay underwater longer and its algorithm is the most conservative and safe (I laughed to myself…). Then the conversation turned to Deepblu — someone said the decompression stop is fixed at 5 m, and someone else said Deepblu doesn't include a decompression segment so it can only be used for recreational diving… That reminded me I had actually filmed a dedicated recording back in July and was too busy to post it.
Key Features of the Deepblu Dive Computer
The most important function of any dive computer is understanding the No-Decompression Limit (NDL) at a given depth — if you don't know what that means, come find me for a refresher (laughs).
I've put together a recording of the decompression procedure as most of you would encounter it on a Deepblu, to show you how to read the display and work through the steps.
Video 1 shows a normal dive in progress (top-right corner shows 1 minute remaining within the no-decompression limit), with the vertical bar on the right down to its last red segment.
Video 2 shows the NDL being exceeded: the Deepblu display flashes and sounds an alarm (the top-right corner shows CEL, indicating decompression mode has been entered), and the vertical bar on the right disappears entirely.
Image 3 shows the display once decompression mode is fully active. The second-to-last row reads dECO-000, which is the elapsed time since entering decompression. Most importantly, the bottom row reads 05.0 08
— meaning you must ascend to 5 m and hold a decompression stop for 8 minutes.
At this point the diver should ascend at a normal rate. If you continue to stay at depth, the required decompression time (currently showing 8 minutes) will keep increasing.
Image 4 shows the decompression calculation still active at 18.1 m during the ascent.
Image 5 shows the partial pressure of nitrogen dropping during ascent at 17.7 m, causing the decompression procedure to pause (the explanation is a bit complex — it relates to the different tissue M-values in the ZHL-16 algorithm). The top-right corner is now showing an NDL, meaning you can stay at this depth for another 4 minutes; exceeding that will re-trigger the decompression procedure and the required decompression time will increase again.
(Note 1) dECO-002 means 2 minutes have elapsed since entering decompression. (Note 2) Although the top-right corner shows an NDL of 4 minutes, dECO-002 still indicates that the decompression obligation has not yet been fully completed.
Video 6 shows returning to 5 m (3–5 m) and beginning the decompression stop; the countdown in the top-right corner is now displayed in seconds.
Image 7 shows the display during the decompression stop: the top-right corner reads 73 seconds, and the bottom-right corner shows a red STOP symbol with a time of 01
.
Image 8 shows that if depth becomes shallower than 3 m, the decompression procedure pauses — you must return to at least 3 m for the countdown to continue.
Image 9 shows the decompression procedure completed: the top-right corner now reads --- and the red STOP symbol in the bottom-right corner has disappeared.
Instructor's notes:
- If you enter decompression mode, ascend immediately at a normal rate to reduce your depth — there is no need to panic.
- The sooner you ascend, the slower nitrogen continues to load into your body, keeping the required decompression time from growing too long. Aim to get within 10 m as quickly as possible.
- Once you reach the decompression depth, simply complete the stop as directed — it poses no harm to your body and is no different from a standard recreational dive.
- The critical risk, however, is entering an unplanned decompression situation with insufficient air in your scuba tank to complete the required stop.
Additional information:
On 11 December 2018, the dive group edited the footage with post-production and added a heartfelt voiceover, making the video much more complete. Share it widely so we can all dive more safely in the future!
