Martin and Steve Thank you for this. Subsequent to posting the question I saw the letter in this month's "Waterways World" and looking at the website referred to convinces me of the sense of Steve's advice.
So - decision is to go for a 60' boat, and almost certainly give the C&H a miss. Martin - thank you for the link. I had looked through your (very impressive) site - but missed that page. Regards Charley
