Stavros, I fully symapthise, having had my Caldercraft Thames River Tug disappear on me for no apparent reason, in Yeovil club's lake, which is a reservoir! A diver went down, but it was too murky for him to see, and several sweeps were made with improvised boat-catching-devices, to no avail. She eventually turned up two years later, when drought conditions reduced the water level by several feet! Unfortunately very little was salvageable, but a friend gave me one he had been gifted, in a dishevelled state, but now restored to former beauty(A tug, beautiful?)
Danny