The first glimpse is of a large black dorsal fin, high above the surface – the unmistakable hallmark of a shark. Closer scrutiny reveals the criss-cross swimming pattern of the tail fin, just above the water which tells the swimming direction. Finally, there is the occasional few seconds where the pointed snout can be seen, telling that it is indeed a Basking Shark (Cetorhinus maximus), a frequent visitor to the Irish coast in spring and early summer. This is the second largest fish in the sea, only bettered by the mighty Whale Shark (Rhincodon typus), pictured in the above silhouette. En route to an evening dive aboard Ocean Addicts ‘Oisre' (pronounced ‘osh-re’), on a perfect May evening, we spotted the tell-tale fin and managed to quietly slip in to the water on snorkel. Even though the shark seemed very leisurely and swimming very slowly, it was difficult to keep up with it for long. But with patience – and luck, watching the swimming movements gave some idea of the direction and most of us got a view of the long body cruising past. It is a privilege indeed to share a moment in the sea with such a large animal, quietly going about its passive feeding on the spring plankton bloom. Unlike its cousin the Great White shark, for whom it has been mistaken, these large sharks averaging 6 - 8 meters and weighing up to 4 tons, survive on plankton alone and do not have the feared jaws or teeth of its predatory kin. Still, many a snorkeller or diver has often asked the question ‘are you sure it’s a Basking shark?’, just before a helpful buddy gives them the push over the side of the boat to find out for themselves!