Truly terrible. It was too low, but this only became clear when the river braided out across a wide

Did we learn anything? Well...

Air Transat were great- my boat went on for free- without any arguing at all- the easiest check in I've ever had with a boat. Thomas Cook and West Jet were also good. AA OK. So, no problems, so long as you avoid Air Canada.
Most of the rivers are glacial so going in August was fine. OK, as expected, the Alberta/ east Rockies creeks were low but any earlier and the Yoho, and probably the Toby, would've been too high. The latter half of July might be the ideal time for the Calgary- Vancouver tour.
It is possible to get a boat to Gatwick by train- I had no problems with the Reading to Gatwick train- in 'rush hour'. Check first whether it'll be OK. Take a roof rack strap.
Tide tables for the Skook wave are available on the www- plan the trip to give you a mid week tide of at least 10 knots (preferably 13-14 knots). It can get busy at weekends. Skook is fantastic.
Stuart Smith's long awaited guide to west BC is still 'coming soon' but there are now guidebooks to south west BC and the West