Fire crews and police were scrambled to reports of boats on fire.
The incident was reported to Coastguard at around 8.30pm on Thursday at East Beach in Lytham.
Firefighters from Lytham and Fleetwood attended believing at least one boat was on fire.
On arrival at the scene firefighters, working alongside Coastguard, made a search of the area but found nothing burning.
A spokesman for Lancashire Fire and Rescue Service said: “We met Coastguard at the scene.
“There was a message over the radio around 15 minutes after our search saying there was no sign of fire.
“We are treating this as a false alarm with good intent.”
Lancashire Police also attended.
They said the alert was likely to have been caused by a smoke bomb or flare.
A spokesman said: “Youths appeared to have lit a fire or let of a smoke bomb.
“However there was no sign of them when we arrived at the scene.
“We attended alongside Coastguard and Lancashire Fire and Rescue Service.
“Investigations are continuing.”