Coastguard volunteers were called to Southport beach following concerns an "object" was seen in the water.
People on social media on Sunday evening said they heard the helicopter "circling the beach" from around 9.40pm until after 11pm. Many said it was "out for a while" as concerns were raised someone may have been in trouble.
HM Coastguard confirmed they received a 999 call from a member of the public who was concerned about "an object in the water at Southport". Southport Coastguard Rescue Team, Southport Independent Lifeboats, and a search and rescue helicopter from Caernarfon were sent out.
