Interesting news today (although, apparently it has been on sale for months)- a US company has chartered a Cruise Ship- the Ambassador Ambition- to be docked at Leith from 8 to 15 August. You have to buy the full week, not individual nights.
The one week rate (which isn't cheap, but then no hotel in the city is at that time either) includes exclusive fringe shows on the ship, transport to and from Edinburgh each day, and is full board.
The week before the ship has done a normal Round Britain cruise to reach Leith.