I've just noticed on the PLA ( Port of London) Website a Notice to Mariners ( M18 of 2015) that states that on May 12-13 and Aug 11-12 a vessel over 210M will berth on the Thames above Margaretness (i.e. in Greenwich/Blackwall area). My list of Cruise Line visits does not match theses dates so think it might be Naval. Does anyone have any ideas as to which vessel that might be referring.