Plot: On Ireland's south-east coast, the three RNLI crews at Dunmore East, Kilmore Quay and Rosslare battle to save a cargo ship that has lost all power and is drifting towards rocks. In Hoylake, on the Wirral, a vast multi-agency effort is required to rescue a mother and daughter who have got stuck in the mud and, 65 miles to the west, in the coastal village of Porthdinllaen, the crew respond to a mayday call from a yacht five miles out in the Irish Sea that is requesting an immediate medical evacuation