Partly due to this thread, and also some past experiences, like hitting an unseen rock at the end of a lake with no one else around, plus I did have a time when my ignition failed at higher RPM's, I decided to start looking for a small lightweight 2 stroke motor (So it can burn fuel from the main fuel tank), and quickly found an Evinrude 2HP from 1973, for a very attractive price on Craiglist, a website here in the USA that is a very well known classified website. I knew mounting the outboard was going to be a challenge to say the least.
There are multiple reasons the motor can not mount on the transom. The starboard side is where I sit to drive and gear up at. The port side location gets in the way of my launching wheel, and with my VHF antenna mounted there I wouldn't be able to turn the outboard towards port. Moving the antenna to the starboard side might work, but it wouldn't leave me with a place to put my fishing rod holder, that holds the dive flag, and the all around navigation light. Sometimes we will also need to put the launching wheels down as we approach the beach. More importantly it doesn't clear the speed tubes, and could chop it to pieces. So no mounting directly the transom. (I really like how Gurnard's boat looks with his two outboards though. Also find it funny how many of us have matching brands from main to kicker.)
In the end I think I am going to use a device very similar to kaman, and store the outboard over the tube, then have it slide out to port for use. We will have to see how it does when the boat is loaded with three divers and all of our gear. The port side is also the lighter side typically as the fuel tank, tool box, and electronics tower do not weigh as much as a person nor dive gear. Over the next couple of weeks, I will have to try to source some stainless box tubing, hopefully from the scrap yard. The plan is to have a receiver mounted on the boat and a shaft that slides in and out, secured by a pin, either in the stowed location over the tube, or ready to use over the water. I do not want to take the risk of removing and installing the outboard while on the water so it seems like the best idea. (Folks had posted prior about the challenges of working in rough water, and I took their statements into account.) The actual mounting is going to be a trial and error since the angles are all over the place, with many different things having to fall into place (VHF antenna, launching wheel, lifting eye which is also the rear tow eye, and things I probably haven't thought of yet). I already took a 2x2 and clamped the motor to it for experimentation. Looks like it will work
So thanks to all who have participated in this thread