Julmops,
It depends on many factors on the day such as prevailing weather, jetstream position and air traffic, but it would be something like the following;
You'll normally depart Gatwick and head out over Wales, over southern Ireland (Shannon) then straight across the Atlantic to Newfoundland, down the eastern seaboard of America, out over the Bahamas then in to Cuba. You'll normally be closer to the coast than shown on the great circle map, but you get the idea.
If traffic is heavy or the jetstream further south than normal, aircraft are sometimes routed over the Azores to the south, then across the northern Caribbean Islands. It's not common to go that way though unless you're heading for the eastern Caribbean islands.
Darren