Complex sentence: Orkney Ferries serve the island with two routes, one of which links Lyness on Hoy and Longhope on Walls with the island of Flotta and Houton on the Orkney Mainland.
Split into simpler sentences: Orkney Ferries serve the island with two routes. One links Lyness on Hoy and Longhope on Walls with the island of Flotta and Houton on the Orkney Mainland.