Douglas lifeboat was called out last night after a mysterious distress signal.
The volunteer crew was called out shortly before 7pm after another lifeboat in the Irish Sea reported the signal.
But despite an intense search using radio direction finding equipment, the source of the call couldn't be traced.
The Sir William Hillary spent some time scanning 10 miles off Douglas but eventually returned to port.
Lieutenant Governor to host special event for charity founder
Two sailings delayed by bad weather
Just weeks to raise £5k to join Dolly Parton's initiative
Aurora forecast for Island's skies tonight
59 bus services on Saturday amid ongoing strike
BikeSafe courses now available for Manx riders
Manxman sailing delays continue this afternoon
Charity's Memory Meadow returns!