Figure 4—At the foot of the cliff on the south side of Ambungi Island near the two underwater caves referred to in the main text.  Above: Russell 
Cook, donning the mask and snorkel, is preparing to take a quick look at the cave entrances, and the nearby coral.  Below: As Mr Cook enters the water, part of the entrance to the left cave 
(the one the creature was seen entering) can be seen at right. (These two photos guided the artist’s illustration of the background landscape of Figure 3.)