Three different 999 services had to be stood down after a "body in the water" turned out to be a bronze sculpture.
Fire, police and coastguard teams were called to Butley Creek near Orford, Suffolk, on Wednesday by a member of the public who had seen the supine figure of a man lying in the water.
The "body" turned out to be a work of art called A Thousand Tides, which has been at the site for more than a year.
A Suffolk Police spokesman described the work as "quite realistic".
The sculpture, by artist Laurence Edwards, was designed to only be seen at low tide and was intended to sink eventually.
However, Mr Edwards said it had "stayed on the surface longer than it should".
He said: "I've always been a bit worried that a helicopter would spot it and want to rescue it.
"To convince someone it's a real person is a great achievement, although I would like to apologise to the poor person who called it in."
The sculpture was a parting gift to the area from Mr Edwards, who had a studio and foundry works nearby for 15 years until spring 2016 before moving to Halesworth.
Mr Edwards' website says his work "attempts to do justice to the locality and its history, by peopling it with large figures that have survived the ravages of the water and the elements."
Suffolk Police confirmed they attended Butley Creek, saying: "Police received a call from a member of the public reporting what they believed to be a body in the river.
"The fire service and coastguard were also called to assist, but a short while later this was actually confirmed to be a sculpture."
A Thousand Tides is reminiscent of Antony Gormley's Another Place installation on Crosby beach in Merseyside, which depicts 100 bronze figures looking out over the Irish Sea.