Bouyancy Compensator Device (BCD)

Researching the BCD I found that designing this for our character is not as simple as it may seem.  According to http://www.underwaterdivingequipment.com/buoyancy-compensators.html depending on where the air is placed around the diver is suited for different types of diving.
In light of this the design best suited for our diver is a vest BCD.
These are examples of them.

I like the flecks of colour in the BCD and some have a reflective strips on them which I think we may incorporate that into our character.