A pair rescued from freezing water at Preston Marina were treated for the effects of hypothermia.
Fire crews from Preston, Penwortham and Darwen were called to Navigation Way at Preston Docks shortly before 10pm on Thursday, March 29.
Members of the public and officers managed to haul the pair - a male and female - out of the water close to a floating pontoon on the Marina, the fire service said.
A 999 call had reported one of the pair had fallen from a boat and the other had followed to help.
But both had got into difficulty and were suffering from the freezing temperature of the water.
They were treated by paramedics at the scene.
Watch Manager Mark Woodward said the pair had been in the water for around 30 minutes.
He added: "There is a safety message here; anyone out on a boat should make sure they act responsibly and have the right life-jackets and life-saving equipment on board.
"Luckily there was a good outcome on this occasion, they were spotted and rescued."