Water police conducted a search in Warnbro after half a catamaran hull was found floating in the water.
Water Police coordinated a marine search operation in the Warnbro Sound area late Sunday afternoon.
Just before 5pm police received information that a damaged piece of a catamaran hull had been located in the water off St Ives car park.
The hull piece is green and appears to be similar to a Hobbie Cat hull.
The second half of the hull was missing.
An initial assessment of the damaged piece of hull suggests it may be an old piece of debris but because this could not be confirmed at the time, a search was carried out.
Rockingham Volunteer Sea Rescue Group vessels and a police helicopter were called in to help.
Water Police would now like to hear from anyone who may have been boating in the area today and who saw the damaged hull.
Also, anyone who may have previously been involved in an incident in the area where a green hulled catamaran was damaged is asked to make contact by calling Water Police on 9442 8600.
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