Ferries to the Orkney Islands run from Scrabster, Invergordon and Aberdeen. The longer ferry routes cost more, but they have the advantage of shorter road journeys. Coaches from Inverness to Scrabster are scheduled to fit in with the ferry sailings. It is also possible to fly into Kirkwall. Boats are generally based in Stromness, but may tie up overnight at other harbours.
Air is provided by on-board compressors.
Nitrox can be mixed on-board most boats for an extra charge. Air, weights and cylinders are usually included in the price, so travelling light to the Orkney Islands and using the boat's equipment is always an option. If you want to ferry your own boat across, there are a number of small slips in Scapa Flow. The nearest to the K ln is at Houton. Scapa Flow is a working harbour and you will need to arrange permission to dive in advance with the Harbourmaster.