This in from Wightlink, in their own words. Ed
Extra sailings (operated by Solent Cat) have added between Portsmouth Harbour and Ryde Pier this weekend (1 & 2 December), owing to the anticipated high volumes of foot passengers travelling to the Festival of Christmas at Portsmouth Historic Dockyard
From Portsmouth Harbour – 0940: 1640 & 1740
From Ryde Pier Head – 0910: 1010 & 1710
