Hi Pat,
As usual you have come up with a thought provoking idea! I was impressed with the Sea Eagle Kayak which you took on the Loop--and Sea Eagle has come a long way from their beginnings.
I have gone to the Torqeedo electric motor--not as fast as a 5 hp, but it comes in pieces which don't weight over 12 1/2# each--total weight 30# with battery. No fooling with gasoline, and pull starts for cold engines!!
The potential problems I see with this Sea Eagle boat are:
Hull Weight: 113 lbs. (98 lbs. with Hull only, 15 lbs. with Transom)
Length 12 ft. 10 in.
The Garhauer davit will handle the weight (rated at 150#), and it is easy to have an extended deck pipe made for just a few dollars more in fabrication material cost and shipping. However it does involve a "dance" along the side deck. I am lifting about 68# and you would be lifting an additional 35#. This will require more force pulling down or sideways on the davit. One of the other posters has solved this in one way, by standing on the opposite of the boat, and pulling across, instead of the same side, where I have control of both the boat as hoisting and the davit. I don't know what the diameter of the tubes is, or if they will fit under your radar arch--which is possible. You are hoisting a boat which is also 3 feet longer than our dinghy (which is 9'6" long) Some of the c Brats are using the Ka boats by Saturn which start at 12' in length and are narrow beam. The weight of the Ka boat is only 48#
There are other cat dinghies:
one of the first ones Is the Takacat. It is lighter, but does have an open transom. It is also probably more expensive. It comes in 8 1/2' to 14' The 9'10" boat weight is 66#, it will take up to 10 hp.
Saturn also makes a similar cat but in shorter lengths: From 9 1/2' (90#) to 12' (125#). These also take larger motors.
Bris also makes an 11' inflatable cat (106#)...So there is selection. Both in size and weight.
Will the cat ride smoother in rough water at slow speeds? At high speeds, definitely yes.(Calm water no difference).
One feature which is important as we age is the floor of the dinghy--most all of them are stable as we step onto the pontoons. But boats without support in the floor, became a trampoline. Not what we need as we step aboard! I favor the high pressure air floor, because it is lighter and easier to put in place than an aluminum or wooden floor.
Any good fiberglass or boat repair shop should be able to put the davit in place. The upper support involves drilling two holes in the lip--and putting 1/4" nuts on the support plate screws. The lower part I make a wedge out of starboard--but PVC lumber could be sured, or one could build up fiberglass. Important is that any holes drilled in the deck must be sealed with epxoy-- this must be done here also. Boat shops and repair places still haven't gotten the word about what one does to prevent core damage--so you have to tell them!
Here is a full photo expo on the Garhauer Davit, how I set it up and use it.
As for balance: you are absolutely right. As we age our balance is not as good. I'm only 10 years older than you. I had a disastrous event 2 years ago. I missed the deck and went in between the boat and dock, causing substantial muscle damage to my leg. I could not get to the stern without Marie bringing the dinghy to me to hang onto until we got the the swim ladder.
Now I plan every move, and think about where my foot and hands need to go to be secure!
