we(three boats)sailed the Clyde about three years ago.
Largs was £13.50.to launch and park the car and trailer for as long as you wanted.If you required assistance i/e.thier tractor it was extra.The slip was into a very sheltered area of the marina.We did not recover there I think it also cost £13.50.(three years ago).The wind to beware of is an easterly,we spent the first night in loch ranza (sea loch on west side of Arran)Rocky shore all round an easterly comes over the island and becomes a katabatic down on the water,I think if you got the the top of a spring tide you could get behind the castle and dry out.
Next we went to east loch tarbet which is nearly a mile in from loch fine.
Very sheltered and they only charged £8.50.for a floating pontoon berth.
Toilet block showers £1.
We hauled out there as I capsized and broke my mast.