I tried to go fishing today. I got to the boat ramp and went to put the plug in, and it was gone. My plug had threads, and it threaded into the hull fitting. It also had a leash that kept it attached to the boat. My boat is a 1998 R-91I. I bought a conventional style rubber expanding plug, but it was too big to fit in the threaded fitting. My question is, do all Ranger boats use a threaded plug? Or was my boat modified or changed by the previous owner?