Wightlink also run a foot passenger catamaran service from Portsmouth to Ryde. Catch the “FastCat” at Portsmouth Harbour station to Ryde Pier Head on the Isle of Wight, then catch the train at Ryde Pier Head to one of the towns on the east coast of the Island. In fact, you can buy a through train ticket from London to Shanklin which covers the whole journey, including the ferry. The FastCat mostly runs every 30 minutes and takes about 20 minutes, it is designed to connect up with the trains, and it’s not usually necessary to book.
Visit www.wightlink.co.uk for more details.