In the 200 years since the RNLI was founded, its crews have saved the lives of over 146,000 people. But even with all that experience behind them, shouts often balance on a knife edge. In Walmer, on the Kent coast, following reports of a major incident involving a small boat, the crew respond to another tasking; on arrival they are faced with mass casualties in the freezing water. In north Wales, the crew race to the rescue of a yacht that's lost all power and is drifting towards a wind farm, with a 75-year-old skipper at the helm - and his two young grandsons below deck. It's all hands on deck for the Plymouth crew as they wrestle with a small fishing boat drifting towards the rocks, with three casualties on board, two of them needing urgent medical attention. And the Aberystwyth crew must pull off the tricky extraction of a woman with a badly broken leg.