I dont even know where to start, but this looks like a great place. My boyfriend bought this boat about 4 years ago from a guy who said he was one owner. It is i think a 1985, checkmate diplomat with a 190 Inboard/outboard motor on it. We took it to ceasars creek in ohio when the water was really low and ran on a rock. The propellor was bent and the pointed fin on the bottom was broke off. The motor would still run but when we put it in gear the prop wouldnt spin. We got someone to pull us to the shore and I parked it. I have been told that I need a new lower unit but I dont have any idea what to look for as far as identifying features to get any numbers or whatever to start looking for the parts. I would appreciate it if you all could point me in the right direction. I can get more information from the boat or the owners manual if needed. Thanks in advance for any assistance with this.