The term Cross Country surfing is a nod to the godfather of modern giant board riding Skip Fry.
If you haven't surfed a board over 12' long you are missing out on one of the great experiences in surfing. Glide and inertia the create a smooth flowing style that really connects a person with the wave they are riding.
1 foot slop to double overhead plus is a realistic range for these boards. Think Duke at giant Castles on a 16 footer.
All this volume gives the added bonus of mobility as well. Surfing multiple breaks over a distance of a few miles is a a very real possibility. You're limited only by how far you are willing to paddle.
As close as you will come to the foil in glide and flow.