There are three ferry companies that operate from mainland Scotland to Orkney – Northlink Ferries from Scrabster direct into Stromness (the heart of the festival), and from Aberdeen to Kirkwall; Pentland Ferries from Gill’s Bay to St. Margaret’s Hope; and the John O’Groats Ferry (no vehicles, passengers only), from John O’Groats to Burwick, in South Ronaldsay.
Loganair also operates regular (at least daily) flights to Kirkwall from Inverness, Aberdeen, Edinburgh, Glasgow and Shetland.
If you are relying entirely on public transport to get to Orkney, the best option is either of Northlink’s services, or to fly. Citylink and Megabus connect from all major Scottish towns and cities to Inverness, from where there is a direct bus service to Scrabster timetabled to meet the ferry connection. Rail connections go as far as Thurso (two miles from Scrabster), from where you will need to get the bus or a taxi to the ferry.