Re: Trailing outboard in vertical position?
Get it as high as you can. I modified a motor toter for my 25hp outboard. My skeg is probably 16" from the ground. I run a strap from the trailer around the outboard and back to the trailer and cinch it tight to hold everything together.
If the roads are nice and your not pulling into any businesses on the way to the lake then you can probably get away with it hanging pretty low (6" or so) but if you start pulling in entrances to gas stations or whatever there's a good chance you will scrape.