In Queensferry, on the east coast of Scotland, an American visitor is caught out by the tide and is barely conscious when the RNLI crew drag him out of the water.

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.