A rescue operation was launched after a member of the public reported a parachutist in the sea - but it turned out to be a Spider-Man balloon.
Two RNLI lifeboats, the Sunderland and Seaham Coastguard teams and the Coastguard rescue helicopter were called out just after 3.30pm on Sunday when the alarm was raised about someone in the sea at Ryhope Dene.
An RNLI spokesman said: "On arrival, Coastguard officers spoke to the first informant, who pointed out the object some distance out to sea.
"Using binoculars they managed to identify the object as a Spider-Man balloon.
"The balloon was recovered by the lifeboat to prevent any further call-outs.
"The incident was a false alarm with good intent and the person did the right thing to call us to confirm no-one was in danger."