My parents used to live in a cottage overlooking The Sound of Sleat. With my interest in aviation I am sure I would have heard of any flying boat base.
There have been 3 airfields on The Isle of Skye. There is another just North of Skye (Plockton), but nothing anywhere near Sleat.
There was (is) a low level route that was up the Sound from South to North, I used to wave at the Vulcan pilots as they went past level with the cottage !! I also had an airmiss there with a C130, but that's another story!