A SEA search is not continuing after a damaged piece of a catamaran hull was found in the water near the St Ives car park at Warnbro Sound about 5pm yesterday.
A police spokeswoman said after no reports of missing people the search was not restarted this morning.
She said the green hull appeared to be similar to a Hobie Cat hull, but the second catamaran hull for the vessel was missing.
Water Police, Rockingham Volunteer Sea Rescue Group vessels and a police helicopter searched the area.
An initial assessment suggested the hull may be debris, but because this could not be confirmed the searches continued last night.
The spokeswoman said anyone boating in the Sound who saw the damaged hull and anyone involved in any incident when a green-hulled catamaran was damaged should call Water Police on 9442 8600.