Looking at the recent news pictures of lightning on the s coast reminds me of how when we moved down from N Wales about 10 years ago that we were horrifed at the amout of lightning down there compared to northern England.
I have no idea about the relative statistics. I had always assumed that warmer areas would give rise to more thunderstorms but the most intense storm I have ever met was well to the north on the west coast of Sweden.
NASA has been recording lightning strikes around the world and has come up with a map showing likelihood of lightning strikes. Looking at the map it is obvious you should not sail anywhere near the Democratic Republic of the Congo. (Florida is also bad news too)