Some keep a look-out for the emerging ‘published’, scanning the expanses for tell-tale points on the horizon; tiny to the untrained naked eye, in more detail through a powerful lens.

On a regular trading route or a voyage in uncharted waters, there’s a chance to close on whales and leaping porpoises, to sense the submarine shoals of tuna or herring, the vast and deadly icebergs.

Sometimes there’s no point of reference, sometimes fish and clouds and waves and seabirds look more or less the same.  They may reward another look.