The first known inhabitants of Islay were farmers from the mainland, who arrived around 4300 B.C. They may have cultivated barley here, but the process of converting it into strong alcohol, through fermentation and then distillation, didn't reach Islay until the 16th century—when it was most likely brought across the water by Irish monks. Today, barley is raised on Islay only for animal feed, and grain for whisky making is brought in—but the island has a seemingly inexhaustible supply of two other substances essential to the fashioning of malt whisky: freshwater and peat (see box below). It also has generous access to a third highly influential flavoring component: the sea. ''To say, as some do, that the ocean doesn't affect the whisky is nonsense,'' says Mike Nicolson, manager of the celebrated Islay distillery Lagavulin. ''Our warehouses are all smack by the ocean, and while the maritime influence may be invisible, it's strong and constant.'' The whisky barrels absorb the air and sea spray, and inevitably a ghost of salt remains to haunt the alcohol. In addition, the peat that smokes and flavors the malted barley before it is fermented contains compressed, partially carbonized salt grass and iodine-rich seaweed. Though there are certainly differences between them, Islay malts thus end up having in common what artist, author, and whisky lover Ralph Steadman has called ''a strong salt-sprayed, aye, aye, Cap'n, seaweedy flavour.'' They taste and smell, that is, of salt and iodine and kelpy sweetness (besides the smoke and yeast and grain that all malts reveal). What I found myself surrounded by that afternoon at Loch Gruinart wasn't just background color, then; it was Islay malt itself.