HMS Ocean is travelling up the Thames towards Greenwich as I write this. She's the Royal Navy's biggest warship and for the next few months will be providing security for the London Olympics. HMS Ocean is an amphibious assault ship (or landing platform helicopter) and the only one of her class in the Royal navy. Onboard for the Olympics will be 8 Lynx helicopters four of which will carry RAF Regiment snipers. Their unenviable job will be to divert, or if necessary shoot down, aircraft which enter the air exclusion zone around the Olympic Park.
HMS Ocean passing Tilbury
HMS Ocean opposite Grays
Apologies for the poor quality of the pictures but these were taken on my phone!