Northlink run services from Aberdeen and Kirkwall to Lerwick. Other services may be available so check with Shetland Tourist Information or the ferry port at Kirkwall.
Once on the Shetlands, a number of roll-on/roll-off ferries connect North Mainland with the smaller islands. For example, Out Skerries ferries run from Vidlin in North Mainland (a pretty village overlooking Vidlin Voe fjord), for a ninety minute journey which can sometimes be so rough that even the cars are strapped down! Or, from Lerwick, the ferry takes 150 minutes.
Fair Isle, Bressay and Noss are both accessible by car and passenger ferry from Lerwick (also Grutness for FairIsle) for an easy seven minute sail (though getting to Noss also involves a three mile walk then an inflatable boat). These ferries can be quite small and the crossings rough.
Yell is accessible by modern car and passenger ferries from Toft on the Mainland – a twenty minute journey. Further ferries run from Yell to Unst (five minutes) or to Fetlar (25 minutes). Some triangular services run between these three islands.
A great inter-island ferry map can be found here:
Boat trips from Lerwick to Bressay and Noss give you great access to seabirds, and also some have colour television on deck which shows pictures taken from underwater so you can also experience marine wildlife as you sail around the island.
Ferry operators may be able to offer multi-tickets, so check with the ferry offices if you’re planning a trip to more than one destination.
Ferries run from a few alternative locations on the Scottish mainland to Sumbugh Airport, 25 miles South of Lerwick. Aberdeen takes 65 minutes, and Edinburgh/Glasgow take an hour and a half - most travellers do travel from the former, possibly because, should there be any disruption to flights, it is often possible to transfer to the overnight ferry. Flights can be more expensive than ferries, but they are generally very much quicker and not as disrupted by weather conditions. Flights operate from Tingwall, Mainland Shetland to the smaller islands – Skerries, Fair Isle, Foula and Papa Stour. Some limited flights also run from locations in the Orkney Islands.
Check with Tourist Offices and ferry/flight operators for up to the minute information, and if they recommend that you book ahead – then do so!