Have just returned from 2 brilliant weeks in Skala. We went on the Island Tour which we booked through Etam Travel. This company's office is situated in the main street down towards the beach opposite the Mi' Abeli taverna, lays a little off the road, you can't miss it.
The staff were very friendly and helpful and to make things easier they have an English guy called Mike who works at this office. The tour was 24 euros each - way below the price offered for the same tour by Thomas Cook. It was a long and very interesting day and we felt the tour was very good value for money. Warning was given up front that admissions to the caves and Underground lake were not included. The caves were Ok but a bit of a leg muscle tester on the way back up !! The lake was really very special and I would defenitely recommend seeing it, it is that good.
Our tour guide was a lovely lady called Helen. Her mix of Information and affiliated stories was just right, she certainly made the day. This is a very beautiful Island and my advice is to let someone who knows the roads do the driving. The road up to Myrtos beach and on to Fiskardo was a bit scarey - very big drops.
We had a very good day and were lucky enough to witness the opening of the casket of St. Gerasimos at the monestary which was quite an experience.
If you go to Skala, which you should - it's lovely and you want to do an Island tour I would thoroughly recommend going with Etam, you will have a long and enjoyable day