Could a person use a device that splits water like for hydrogen fuel cell car but keep oxygen for scuba diving?

I heard that this canadian invented a device that splits water into hydrogen and oxygen. Companies use this device to store hydrogen in tanks until it can be used for a hydrogen fuel cell car(like they do in iceland). My question is can you store the Oxygen instead to go on the ultimate scuba adventure? My dads a scientist, but we’re not talking right now so I thought I would ask here.