MiniDive Mini Scuba Tank 0,8 L Aluminium, DIN Filling Station, Holding Harness, Diving Equipment Underwater Breathing Unisex

I haven't bought this product, but saying a 0.8L tank can last 10-15 mins is not just misinformed it's potentially dangerous. A 0.8L tank filled to 200bar is 160L of air. Regs become unreliable below 15bar. So that's realistically 148L of air to start with (with no reserve). The deeper a diver goes the more air is consumed with every breath. But let's say this is just for shallow dives, no more than 10m. A typical diver breathes around 20L per minute at the surface (SAC/RMV). So at 10m that's 40L per minute, that only gives a little over 3.5mins of breathing time. (And that's being conservative, if they are breathing heaver or go deeper this could be down to 2mins of air). Dangerous.

In Scuba Diving we; “Plan the dive and dive the plan.” When one considers ‘all’ the safety precautions mentioned in any dive plan - including the all-important amount of reserve air needed to get the diver safely back to the surface, the user of this item has to ask “how long will one of these last underwater?”In considering my answer, I must take issue on 3 points:1. If you have to fill this item from a large cylinder then why not buy that larger cylinder in the first place. Remember, having decanted air (NOT Oxygen!) from your large cylinder once, you have reduced the pressure in that large cylinder and can only fill your smaller cylinder to a maximum of that reduced pressure when filling again. Put simply, you have less air after every refill.2. One of the drawbacks for travelling divers is paying for ‘excess baggage.’ Whereas airlines are happy to charge for all your diving gear and cameras, they will NOT allow diving cylinders of any size - even if they are empty. Compressed air cylinders are classified as DAC - Dangerous Air Cargo and are not allowed on commercial flights.3. Although human lungs continue to fill and empty as one might expect during diving, we use twice as much air at 10m (33 feet) and three times as much at 20m and so forth. This because the diver is breathing air at twice the normal thickness at 10m and three times at 20m (Yes, six times at 50m!). It is not uncommon, therefore, to see technical divers (who go really deep) wearing four large cylinders as they depart the surface. It is also common practise for all scuba divers to return to the surface with far more air than this item could ever carry.My answer to that question is, therefore “Not long enough at any depth!”NM