Ramsey's volunteer lifeboat crew was called out after reports of people in the water on Saturday.
The lifeboat launched at around midday after a member of the public raised the alert.
The RNLI crew spent around three hours searching the sea off Queen's Pier, but couldn't find anybody.
On their Facebook page the crew said the call had been a well-intentioned false alarm, and people should always ring 999 if they're worried about people in the sea.
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