The release TomH pointed out will work, but I’m leery. I used a similar style release that mounted to a pylon over 20 years ago. We quit using it after some close calls. When a tricker falls fast and hard towards the boat, the load on the line can be so great that it takes a significant tug to release the mechanism. The curve round piece gets pushed into the lower moveable arm with such force that it becomes difficult to actuate. The version I had utilized a bearing in the lower arm to help allow the upper arm to release properly. Essentially for the two pieces to roll past each other. Maybe it helped, but it wasn’t perfect. We moved on to the Masterline style that has to be kept under tension by the pin person, otherwise it self releases.
I know the OP is trying to work within his tow boat limitations but I wanted to share my experience with a similarly designed release.