Whiskies, you mean? Dozens. And it is indeed the water. In fact, the word 'whisky' itself comes from the Gaelic 'uisge beatha', meaning 'water of life'.
More than 2,500 brands of Scotch Whisky are sold all over the world, of which as many as 200 are available in the home market. Many of them are sold only locally or to private clubs and individuals.
Scotland has a climate well-suited to growing barley (but less so to growing hops for beer, or grapes for wine), so it's unsurprising that someone there worked out how to use barley to make a beautiful drink ;-)