We had timed our previous dives so that we could be at Shiprock at high tide. An easy dive off a boat, we anchored carefully south of the float and again on twins slipped over the side.  There were a number of other divers there and I bet they wondered what we were doing diving this site on twins. They were not to know we were boat diving and having done 2 dives on the twins there was not a lot of air left in them by this stage.  We visited the bubble cave, found some neat nudies and a good variety of other fish that are common at Shiprock.  Viz was about 8m, not bad for this site.  With 20 bar left in my twins I headed up and we headed home.