Delays of up to 20 minutes on South West Trains between between Exeter St Davids and London Waterloo and between Weymouth and London Waterloo due to speed restrictions between Raynes Park and Wimbledon.
Exeter/Salisbury services are start/terminating at Basingstoke. London Underground accepting tickets.
More top news
More than 150 boats are taking part in the World Pilot Gig Championships - the biggest in its 27 year history.
A minute's applause will take place during the Army-Navy rugby match in memory of Captain David Seath, who died during the marathon.
RNLI lifeguards will start patrolling beaches in the region this weekend as the 2016 summer season get underway.