Boats locking out of Limehouse Basin into the Thames tideway to take part in IWA South London Branch's Campaign Cruise past Parliament in May 1998. That's me in the foreground steering Felis Catus II. The photo was taken shortly after low tide. The tide lock is in the background, and the large structure carrying the name of the marina is Narrow Street swing bridge. The latter has to swung whenever yachts want to leave the basin, and on high tides even for narrowboats. On some high tides boats actually lock down from the tideway into the basin.