幾年前去過， Waterloo Station to Southampton by Train, ~1.5 hours, See

https://www.google.com/search?ei=P2jmWvqWIYz-jwSm14_IBw&q=waterloo+station+to+southampton+by+train&oq=waterloo+station+to+southampton+by+train&gs_l=psy-ab.3..0i30k1.13216.15722.0.16854.8.8.0.0.0.0.150.1002.0j8.8.0....0...1.1.64.psy-ab..0.8.999...0i7i30k1.0.-TfmdW8gYDA