The sea over the coral platform varies in depth with the tides. At low spring tides, much of it nearest the beach is exposed, while at high tide the depth of water varies from four to five feet near the beach to ten to twelve feet or more at its outer edge.

The long awaited cyclone came at last and its effects were apparent on the island for eight or nine days, viz. 22 to 29 March, as it passed on a westerly course to our north. The cyclone was nearest to Willis Island causing roughest seas and weather on 26 and 27 March.

In the circumstances with a little doubt still lingering in our minds, all three of us watched the behaviour of the sea very closely. It was fascinating and awe-inspiring to see each successive swell rear up like a wall of water some 30-40 feet or more in height, with the foaming white top blown forward by the gale and the base retarded as the water from the previous swell was sucked back into the intervening trough, like a raging waterfall over the reef edge.

On going out at daylight when seas were roughest, we found a seawater lake over a patch of grass at the low northern end of the island, where water at high tide had spilled over from the beach. At first we were a little alarmed. With the falling of the tide, the lake disappeared through the porous ground below. This experience only confirmed the view towards which we were inclining, viz. that the island was safe from inundation even in the roughest seas.

Bureau of Meteorology