UK's most dangerous shipwreck SS Richard Montgomery lies at the mouth of the River Thames and is protected by an exclusion zone that all craft are prohibited from entering.

The 250-metre exclusion zone is marked by four large yellow buoys in a diamond shape.

This morning (October 20), Briggs Marine vessel Cameron was seen carefully replacing one of these important navigation markers.

The wreck which sank with 1400 tonnes of ammunition onboard in 1944 is situated just 1.5 miles north of the town of Sheerness in Kent.

The UK Gov are still working to progress plans to remove wreck's three masts above the waterline - when this happens, the yellow warning buoys will then be the only visible warning of the wreck's dangerous presence.