The inventor’s site:

Inventor develops ‘artificial gills’

General components of the system
(Final product will have the separator, batteries
and spare air cylinder in single enclosure)

An Israeli inventor has developed an underwater breathing system that literally squeezes oxygen directly from seawater, doing away with the need for compressed air tanks.

Called “LikeAFish”, the battery-powered artificial gill system aims to extract the small amounts of dissolved air that already exists in water to supply breathable oxygen to scuba divers, submarines and underwater habitats.

The system currently exists as a
laboratory model

Experts have some concerns about its practicality as an alternative to to the aqua-lung or
the re-breather for a diver….. but its greatest potential could lie in underwater habitats.