My wife and I once planned to spend a day exploring the St. Croix River in our boat. It is a 15 foot Glastron tri hull and at that time had a 60 hp Johnson outboard motor.
We drove up to the Minnesota side of Interstate park and launched the boat at the public boat launch. We got all our things in the boat and pushed off into the river current. I then tried to start the motor and heard the starter kick in but then heard a splash. I looked back and the motor was gone! The transom motor mounts had broken and when I had tried to start the motor it had jumped right off the transom into the water.
The motor was still attached by the electric and fuel lines but was hanging into the water. I took a rope, tied to the boat, and swam to shallow water and was able to pull the boat back towards the dock. However, once the motor touched the bottom it acted as an anchor and I could not pull the boat ashore. My wife held the boat in place with the rope, and I and another man lifted the motor onto the back of the boat. I was then able to dock and trailer the boat. That was the end of our exploration of the St. Croix River.