A black drum believed to have been left in the sea by fishermen led to an emergency service call-out.
Sunderland Coastguard Rescue Team received a report of concern after an object was spotted in the water just off Roker Pier.
A spokesman for the team said: "We were called out this afternoon to verify an object in the water just of Roker Pier.
"On our arrival we met with the first informant at the Balmoral Guest House, whom pointed out the object to our team.
"The object turned out to be what looked like a black floating drum, possibly used as a fishing pot marker, and not something more sinister.
"We take this opportunity to remind fishermen that if using these type of devices to mark their item with an appropriate flag.
"Fortunately a false alarm on this occasion, but a call made by the member of the public with good intent."
They added anyone reporting a coastal emergency should call 999 and ask for the Coastguard.
The incident happened at 1.20pm yesterday.