Rob,
We have a bridge here over the Camden Haven river, that has been used by people to lower their masts, (never done or seen it done myself), & would be tricky here as you only get a brief respite from the tide, find a bridge in a no/slow tide area, or wait for a more sensible suggestion!
Cheers Mr Greg, your "too much armchair cruising" comment got me off the armchair yesterday to go for a little sail , was a beaut day. http://www.youtube.com/user/TopHatShaun ... SRRYuqgMXM