David Hamilton, who owns and runs Red's Orkney Tours, is a qualified tour guide. He grew up on one of our smaller island – Flotta (which to my shame I have not actually been to myself, but will now have to as he tells me that for lovers of history such as me, the place is wonderfully rich in it).
David runs a great-looking 8-seater Mercedes minibus and can offer both pre-planned tours of the main sites to cover various themes and also organise more customised tours and itineraries for customers with particular interests.
For more details and to book, do look at his website here.