In fact, an Australian start-up company has recently come up with a more professional version of this DIY project. It is called the SCORKL . The idea behind this project is to make shallow scuba diving accessible to everyone with maximum safety… Their kick starter page details that the device is intended for trained scuba divers below a depth of 3m ..Humm
The Scorkl is only intended for shallow water use. We recommend that scuba-trained users not use the Scorkl below 10m and that non-scuba-trained users stay above 3m in depth as mentioned above.
Each Scorkl comes fitted with a pressure gauge so that the user can know how much air remains in the cylinder at any time.