Thames CG requested the lifeboat to launch following a report of a male stuck in mud half a mile off the Alberta Caravan Park, Seasalter. Kent Police and Fire Brigade were on scene, and an RAF rescue helicopter had been tasked. The tide was flooding.

The lifeboat got as close as depth of water would allow, then crew members Dave Parry and Mike Keam waded the rest of the way, guided by firemen at the waters edge who were illuminating the casualty. 

The crewmen found the man standing in thigh-deep water. He wasn't actually stuck, but had injured his ankle and was unable to walk. With the water level rising, the lifeboat was brought alongside the man, who was lifted aboard and wrapped in a thermal blanket. Once he was safely on board, the helicopter, still about 15 minutes away, was stood down.

The lifeboat then returned to the boathouse, and the casualty was subsequently taken to hospital by ambulance.

More info here