Water Vent block

These blocks look like little volcanos that are slightly smaller than a block. If they are underwater they will spew bubbles at a slow rate which unlike the bubble colloms will not move you but will give you air. I believe that these should be added as a way to get air without having to be dragged down or pushed up. Plus these would go great in water caves to make them more welcoming to players since most tend to avoid them. Vents would also look nice in oceans and as a decoration for the player to use.