Old Number 12 was named after an old scuba tank numbered #12 that was found on the reef, having presumably fallen off a dive boat in rough weather after going missing for some years. The western edge of the site is a classic vertical wall beginning around 55 feet and is the natural starting point. From here, divers head east along the wall for a remarkable ascent up a long slope adorned with waving fields of sea fans and soft corals — staying just above the tips creates a hypnotic sensation as the fans move together in unison.

The gradual ascent typically leaves some bottom time once you reach the top, making the edge where sand meets reef worth exploring. The small lip created by the abrasive sand eroding the rock is an ideal spot for spotting creatures. Look for Soapfish lying motionless on their sides on the bottom, keeping a beady eye on you — they earned their name from fishermen who noted that when caught, they release a bubbly slime resembling soapy suds.