Not much, but all I need. Customised to have as little tangling parts as possible.

 Corona mask which I found on The Philippines for 13. The tank-banger was a necessity on Bonaire, where there were so much to see, and I had no camera of my own. 6.

Suunto Vytec DS with wireless transmitter, bought new in Denmark. 625.

3 mm short NeoSport, bought new on Bonaire for 80$

Used SeaQuest Predator, bought on Bonaire for 65$

Short powerfins from Zeagle, bought used on Bonaire for 15$. Real good for fast removal in the surf! Light and easy to travel with.

 Small but strong torch; Frogman Neon LED-Lenser.
4 AAA batteries: 50 hours. 53 in Denmark.

Used Sherwood octopus, bought on Bonaire for 175$. Added a new ScubaPro Air 2, MK 4: Combined inflator/secondary regulator (125) and a wireless transmitter: Two hoses less!

Cressa shoos, bought on Bonaire for 38$

2 Ixus 75. Brilliant small camera, bought used for 135 and 80
The first which I bought new for 200 drowned after one day and one minute...

Canon WP-DC14 Waterproof Case for the Ixus 75, 200
A few rubber pieces, and it fit my Ixus 70 as well.