The Branksome Pipe doesn't sound that exciting, but it's the entry route to the Branksome Reef that runs parallel to the shore.
The outfall pipe is a gentle 100m walk from the Car Park, so far easier than Chesil. Once in the water, it's a gentle 60m swim along the 3ft diameter pipe to around 8m. Here you have a choice of heading left or right along the reef. Don't make the mistake of walking along the top of the breakwater in full kit as there is no "stride entry", you need to enter the water from the sand on either side!
Location: 50°42'22.0"N+1°54'28.7"W (approx)
Access: Shore Dive