Wondering what the smallest dinghy size is that will accomodate a 9.9hp motor.. I want to use it for my Catalina 30 but I am thinking the dinghy will likely be too big. I have a mount/lift on the transom where I can mount the motor and then lower it to the dinghy if I need to use it.. otherwise I was hoping to store the dinghy on the bow.. or possibly mount it aft.
If I'm reading between the lines correctly, you already have a 9.9hp outboard and are trying to fit a dinghy to both it and your C30.
How about you go about it another way. Find a dinghy that you are comfortable with in terms of size, weight, handling, etc. Then size your outboard to the dinghy -- if the 9.9 works, great! If not, then swap or sell your 9.9 for an outboard that will fit. I think this approach will be a more suitable one that will pay off in the long run.