HMS Ocean Olympic security centrepiece 04.05.12
11Day three of a major Olympic security exercise has seen the Royal Navy's largest ship sail up the River Thames.
HMS Ocean arrived at Greenwich in east London where it will act as a launch pad for eight Lynx helicopters and a base for Royal Marine snipers.
It is the final phase of the exercise named Olympic Guardian, which began earlier this week in Weymouth and in the airspace over the capital.
Smaller crafts and patrol boats accompanied the ship as part of the maritime security plan.
The snipers have extensive experience of shooting the engines of fast vessels in the Royal Navy's fight against the drug trade in the Caribbean.
Capt Betton said the ship would provide vital assistance in stopping any potential threats on the river.
"The versatility and manoeuvrability of helicopters allows them to get to the scene of action very swiftly to identify and to divert any surface vessels that are heading up the Thames, to ascertain their intentions and if necessary take action."