Location
The best way to get to Sagres is to take the motorway to Lagos, then follow the N125 to Vila do Bispo and further the N268 to Sagres. Tonel Beach lies just next to the parking area at the fort on the western side of the cliff.
The Spot
Tonel Beach is a very good surf spot, although it is supposed to be also good for windsurfing. The waves we have seen during our stay (eastern winds) were very smooth. They were breaking on one side of the beach and running along the whole beach to the other side.
Wind
The prevailing wind direction is normally west (on-shore). Then you will see in Tonel huge swells coming into the bay. During our stay we had eastern winds (off-shore). The water was very flat with nearly no wind waves. However, there were waves of at least 1-1.5m, rolling slowly into the bay.
Accomodation
As said for Martinhal, it should not be a problem to find a place to stay in Sagres.
And...
...follow the road to Sao Vicente, the most southwestern tip of Europe and enjoy the view down the very impressive cliffs. You can also take one of the small roads back to Vila do Bispo and drive to a beach on the west coast (Aguia, Castelejo etc.). Those beaches do not seem to be very suitable for windsurfing (a lot of rocks), but the setting is brilliant - a very wild coast with only few people. Take your time to have a good coffee in one of the cafes.
