I don't think Arctic Char Are a protected spieies.
As for the hire terms, not too bad, it's the 8 hours bit I don't like. That makes it a bit steep imo.
There's very little value about in terms of boat hire apart from Loch Awe. £40 for the first day then £20 per day there after. He also let's you keep the boat over night as long as you report back in at 8am and that is waived if you are staying locally.