Air Buddy Octopus

The Air Buddy Octopus, a big improvement over the old kind.

Look at the Air Buddy in the picture.
It is the tiny black mouthpiece to the right of the normal  regulator second stage.
Actually, if you don't count the large chrome mounting nuts which are identical to those on a normal 2nd stage, all you can see of the Air Buddy is the silicone mouthpiece.
All the functioning parts are hidden inside where they cannot get in the way.

Here's what it looks like mounted on your regulator.

You see it mounted in its normal position on the end of the yellow octopus hose of the regulator in the picture. It obviously eliminates all the problems caused by the bulk of an extra normal 2nd stage hanging on your regulator. It does not eliminate the hose. It makes the hose less of a problem.
If you leave your octopus trailing behind, it cannot get caught in coral, mono-filimant line or fishermen's nets.
If you tuck it into your BCD, you can tuck it under any strap or stick it in any pocket and it will pull free in an emergency without ever hanging up.

Transfer air from your air supply to inflate your dive buddy's Bcd safely

If your dive buddy runs out of air you have two problems to solve.

1. You must give him access to your air supply to breathe until you get to the surface. You can give  him the 2nd stage regulator out of your mouth to breathe.  He will feel comfortable with that. You can continue to breathe with your Air Buddy.

2. You have to get him safely to the surface.  Besides not having his own air to breath he might also not be able to inflate his BCD to gain buoyancy.  He will probable resist you if you try to jettison any of  his gear to make him lighter.  You don't have to stress yourself to liftg him to the surface.  You can simply take the Air Buddy out of your mouth for a few seconds, press it to the mouthpiece of his BDC and shoot air into it, guiding him in a controlled ride to the surface.    

air buddy to bcd