Dropped off boat onto reef. Viz not so good at first – lots of plankton! Made it down the reef wall to about 30m and finned out into the blue. A big Manta passed between us and the wall at about 20m. Stayed in the blue for about 15 mins looking for big stuff! Nothing this time except a couple of grey reef sharks cruising the reef wall below us. Kept reef right shoulder and drifted with current up wall and finished dive in the shallows. Saw areally nice giant clam. Cloudy day and wicked thermoclines – felt really cold! Happy to come up with 90 bar. Getting spoilt but really nice dive.