A land, sea and air search was triggered late last (Saturday) night by several reports that a small boat had collided with the East Cowes breakwater.
Cowes RNLI Lifeboat was joined in the search by coastguard teams from the Needles, Bembridge and Ventnor together with a coastguard helicopter.
As well as covering the breakwater, the search extended from the harbour to a stretch of the River Medina beyond the floating bridge.
But the operation was finally called off without any sign of the boat or anyone in distress.
The lifeboat, which had launched at 9.45pm, returned to station just after 12.30am.