I have a 34 ft Pacific Seacraft, and years ago had a similar problem. I ran a piece of 3" aluminum channel from the upper stern rail nearly to the water. with the flanges facing forward. It was clamped to the stern rail at the top and secured to the dinghy towing eye which passed through a slot cut in the center of the channel with a wedge. Two plates a foot or so above the water were bolted one on each side to the channel flanges. They extended aft and were each bolted to short lengths of angle that were both in turn bolted to the outboard motor mount to which our 8 hp Nissan was clamped.
Now, it's been 10 years or so, and this is by memory. It's been under the port settee since. Out of sight and mind.
Now, it's been 10 years or so, and this is by memory. It's been under the port settee since. Out of sight and mind.