Episode 1

Horatio Clare joins the crews of lifeboats based on the river Thames. Established in 2002 in response to the inquiries into the Marchioness disaster, the four lifeboats are permanently manned and have to respond to a distress call within 30 seconds. The boats are not like familiar sea-going lifeboats but are jet-propelled, capable of travelling at 40 knots.

Horatio attends a night shift with the full-time and volunteer crew at Tower Station, near Waterloo Bridge. He witnesses rescue training and gets a call-out. Moving on to Gravesend, he joins the crew on a melancholy mission, searching for someone feared drowned.