Whenever their pagers sound, the volunteers of the RNLI immediately find themselves under pressure.In Port Isaac, on the north coast of Cornwall, the crew race to the rescue of a female casualty with a spinal injury; she's in a precarious position on a rockface, with the light fading. In Pembrokeshire, south west Wales, the Little & Broadhaven crew receive a mayday call about a capsized dinghy with three people in the water.In Mudeford, on the Dorset coast, a search for a missing kayaker quickly escalates when it emerges that there are six more kayaks unaccounted for. And in Eyemouth, on the east coast of Scotland, the crew respond to an unusual rescue: a swan in the harbour that's become tangled in fishing line.