With the advances in computer computation, fluid dynamics and mechatronics, would it not be possible to have an outboard motor that is a mechanical tail fin?
This is probably not for aquatic gear-heads but rather contemplative fisher-people and those searching for holiday relaxation on the water. As the goal is trying to be at one next the water the power source probably should be chemically stored electricity.
The outboard would be decked out with fluid flow sensors to maximise the best force and angle. There would be no cavitation as the fin would be slightly flexible and pressure wave stroke would be calculated on a stroke by stroke basis.
Going backwards might be a problem so just go around again, as time is not an issue. Slowing up would still be good with the right stroke. Error messages could be done in softened Dolphin clicks and whistles.
If a bit more turn responsiveness is needed, fly-by-wire attachable pectoral fins and a computer upgrade are available.
So with a quiet waving, I'll see you out on the water .-- wjt, Sep 02 2017 Faux Fish https://www.youtube...watch?v=KEFVico5OTUalas not motorised... yet [2 fries shy of a happy meal, Sep 02 2017] http://www.pbo.co.u...ver-the-stern-20811 [pocmloc, Sep 06 2017] This would be much safer for divers, marine life, etc. [+]-- 8th of 7, Sep 02 2017 There's a technique of using one oar dipped over the transom of a small boat and wiggled in a figure-8 movement without lifting clear of the water. Its not easy but it works. <link>-- pocmloc, Sep 06 2017 Also used with coracles, but in the direction of travel to pull it along.-- 8th of 7, Sep 06 2017 Sculling - I tried it, after having been given a ride by a fellow who was good at it.
I borrowed his boat to row out to his houseboat and thought I'd scull my way out there. I wound up getting naked and swimming, towing the boat.-- normzone, Sep 06 2017 I did think of the tricky figure eight motion but thought nature knew better.-- wjt, Sep 08 2017 random, halfbakery