This is a seaside swimming walk along the start of the South West Coat Path along sandy beaches. 11.6 miles (or catch a bus at any point).
Catch the London Waterloo 9:35 (Clapham Junction 9:27, change Woking) to Branksome 11:29.
Buy a £15 SWT Fever promotion ticket to Wareham. No railcard discount. Two hours each way, bring a book!
Return : Bus from Swanage at xx05. Then train from Wareham at roughly xx28, xx53 until 1953, 2042.
Last reasonable connection from Corfe: #40 bus - 7.05pm from Swanage, 7.23pm from Corfe, 7.36pm Wareham for the 7.53 train, arr Waterloo 22.23).
Walk Directions and map : http://www.walkingclub.org.uk/book_3/walk_73/index.shtml
This walks starts with a slow descent to the sea through a forested chine (a steep sided valley). It then follows the sea, along a mixture of promenade or for a few short stretches, the sandy beach itself. This stretch is lined with cafes and beach huts, and can be quite busy in summer.
Soon expensive Sandbanks is reached, where there is a short 'chain ferry' crossing (every 10-20 mins, takes 5 mins, 2009 fare: 90p) across the entrance to Poole Harbour. Lunch is at a small cafe just after the ferry with views over the Harbour, or bring a picnic, and have it on the beach at the start of Studland Bay
After lunch, the walk follows the South West Coast Path along the beach past the National Trust's Studland Bay, a sandy beach backed by sand dunes. While any part of this walk is good for swimming, the start of Studland Bay is particularly good as there is a sandbar offshore which keeps the sea shallow, and so, quite warm. The middle of Studland Bay is a well known Naturist Beach, which is quite busy on a warm summer's day. There is an alternate path through the heather of the NT's Nature reserve behind the beach.
At the end of the bay, there is a cliff top pub with an idyllic location.
Continue out to 'Old Harry', a stack (pillar of rock in the sea) which has been visible for the whole walk so far.
The path climbs a small hill (117m), with fine views. Continue south along the coast to Swanage.
Bus from there back to Wareham for the train
From Swanage/Studland/The Ferry, the #50 bus (via the ferry) to Bournemouth (1hr 10 mins) may be quicker as there are more/faster trains.
There is a group bus ticket - £18 for 5 people
This walk does not have a leader - so you'll need a copy of the directions (see link above). Meet up on the platform at Bransombe Station, and enjoy