Read and submit reviews for the Shearwater-KV.
I read people say it is not for beginners.....I can't imagine why. It is incredibly stable and could have been made 2 inches skinnier. I got mine used having been previously owned by multiple people. There are many hairline cracks in the gelcoat both on the deck and hull. I don't know if it was banged around or if it just has a poor quality gelcoat job. The Shearwater should fit most people comfortably...I'm 6 ft. and 225 lbs. I may mount a surfboard skeg to the hull to straighten things out.
This was on flatwater, so I don't know about rough water handling. The under stern rudder worked very well and would turn it very quickly. But it did slow it down a lot when I really cranked it over. Makes sense. I really like the option of using the rudder or not so I've removed it and going to replace it with an over stern one. Also, some of the water I paddle in can get shallow so the over stern rudder will help there.
Couldn't tell anything about the inherent tracking or maneuverability of the boat because the rudder controls that. Now that I've removed the rudder, it'll be interesting to see what it does.
Watch out for rear quartering winds. In a 25 knot wind it will weathercock even with the small skeg. I haven't had it out in big waves, but even a very exprienced friend said he could probably not stay on it on a big wave. And he can handle an 18' boat in big water better than anyone I know.
The former owner raced it fairly sucessfully on San Francisco Bay. He replaced it with a racing surf ski. He warned me off of using in really rough conditions like off the Mendocino Coast in winter. On the other hand. It is a beautiful, rugged, and very well made boat. It was designed by a boat architect and it is very well designed. The only SOT I know with bulheads.
Did I mention it is over 18' long and 24" wide? I guess it holds a ton inside, and that might improve intial stability. I don't know. I travel light. It is also very fast. It can run with the big boys. Sit on top, or sit inside. Just a few sit insides like the Seda Glider have an edge for speed, and not a big one.
If you do not do open ocean trips it should do just great. If you do open water, then buy the Shearwater for speed AND get another boat for the rough stuff! Bottom line is: mine is not for sale.