An interesting idea, but such a skeg would tend to come out of the water in following seas and waves--no different than a rudder, but I think part of the strength of skegs is their tendency to stay submerged and working in seas.

I vividly recall following my instructor along a piece of coast where we had strong wind and tide coming from the port quarter. My ruddered boat was continually being turned into the seas and wind, and no amount of leaning, sweeping, ruddering could keep me on the line I wanted to follow. I basically made it along that stretch by zig zagging, which ate a lot of time and put me a long way behind. The instructor, in his skegged boat, just paddled along as though there were no quartering weather. At least I did not see obvious evidence of corrective strokes and leans as he pulled away from me.

I don't know how much that had to do with a skeg vs my inexperience, but I suspect the skeg helped. I will disclaim that by noting that the Eskia I was paddling at the time is more subject to weathercocking than the Explorer he was paddling. And his 5-star vs. my 3-star "rating" at the time probably had a lot to do with it!

Can anyone elaborate on skegs effect in such situations and on the idea of mounting them at the stern?

: I don't like the idea of extra lines of a rudder and necessity of a foot rest
: that moves.

: Does anyone use a skeg that is mounted on the stern like most rudders, but
: can't be turned but only dropped straight down?

: This cuts out cutting through the hull. A good thing I believe.

: Is a skeg as aft as possible more or less effective than one more forward?