DIDEEP Scuba Tank Diving, 0.5L Capacity Mini Scuba Tank,Dive Portable Lungs for 7-10 Minutes Underwater Breathing, Diving Lung Tank Suitable for Emergency Rescue, Underwater Exploration

The only drawback, it takes some effort to pump up to full capacity. Otherwise, these are fun! Nice carry case and easy to use. Worked well...

The media could not be loaded. This half-liter of air offers a quick and relatively easy way to swim underwater with a little bit of air. In making our video review, we found that while swimming, for a 6’2” 250 lb male, air lasted about 4-5 minutes. Keep in mind that swimming underwater uses a lot more air than staying still underwater, so it is possible that this could last 7 minutes or more for sedentary activity. The five-minute video shows our impressions and that this a usable, low cost solution for trained divers. Note the beginning of the video showing that using a manual pump is not easy, with about 500 strokes required to fill just this small tank. Also be aware that SCUBA equipment experts tell you not to store tanks charged with air, but just to keep 200 psi in the tank (versus 3000psi) to keep the tank dry and corrosion-free. These aluminum tanks do not have nearly as much corrosion difficulty as steel, but should be inspected and (re)certified every 5 years. Another observation was that the mouthpiece/regulator does not have an easy way to purge water if you should get a big gulp (a skill practiced in SCUBA certification). Photo 3 shows the glow-in-the-dark feature of the pressure dial, and it is very readable. The final photo shows a loose cap at the top of the pump: each pump part needed tightening to work well and fill the bottle. There is a lot to be careful about, but for us, this did work nicely and is an excellent solution for diving around our dock, finding lost sunglasses, or recovering fishing poles!