Christchurch [CHR] is on the main Waterloo [WAT] Weymouth [WEY] line. 

Christchurch Quay is a 15 minute walk from Christchurch Station [CHR] or 5 minute taxi ride.

Trains from Waterloo [WAT] stop at Christchurch at 52 minutes past the hour.

Trains from Poole [POO] and Bournemouth [BMH] stop at Christchurch [CHR] at 13 and 30 minutes past the hour

Stompin' finishes at 10pm.  The next train to Bournemouth [BMH] leaves at 23:08

The next train to Waterloo [WAT] leaves at 22:20, or to Southampton [SOU] (only) 23:20

SUBJECT TO SW TRAINS TIMETABLE