A lifeboat crew and coastguard rescue officers were alerted following reports that a woman was in difficulties in the sea.
But after a shoreline and beach search in Lowestoft, nothing was found.
A spokesman for Lowestoft RNLI Lifeboat said: "Lowestoft Lifeboat and the Lowestoft Coastguard Rescue Team were called out at 4.46pm on Monday, October 28 to conduct a shoreline and beach search following reports of a female up to her waist in the sea somewhere along the coast at Lowestoft.
"While coastguard officers focused their search on the South Beach and Claremont Pier area, the lifeboat crew with Coxswain John Fox in charge used a searchlight to illuminate the shore as the lifeboat travelled from the North Denes caravan site to Pakefield Church but no one was found.
"The lifeboat was stood down and returned to her mooring at 5.45pm."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here