In a holiday resort on the Lincolnshire coast at a Bank Holiday weekend the last thing Iain Macready, coxswain of the lifeboat, wants is a spate of hoax calls. But he and his crew have to deal with these just as they have to answer the genuine calls that inevitably come at holiday time. When a storm breaks over Saltershaven, Macready's own daughter is missing at sea in a sailing dinghy, whilst duty obliges Macready to set course away from the area where she may be to answer a distress call from a coaster.