The loch is not really shut on the 12 Aug, its just that bunches of "toffs" come up to the lodge for the start of the shooting season and they get first dibs on the fishing. But its worth checking with the Head Keeper as he says himself that most of them are not interested in the trout fishing and the boats can be available until about the 15th Sept. Worth a phone.
When you say the top of the loch I take it you mean where the river comes in.
I know what you mean about the toffs, i believe now you are banned from fishing the top of the loch where the burn/river comes in at the bridge!. Use to be a hot spot for big trout just down from the bridge, i can get tickets through my mum as she works for the estate but i think you would have to be well conected to get a ticket after the 12th!
