I'm considering a double kayak for my next project. Being relatively new to kayaks (and thrilled with the handling of my Guillemot S&G), I would like to start transitioning my family to kayak use - from canoe use. However, I don't want to give up the efficiency, tracking, turning, and overall intimate feel of my single.

In general, how does the handling/efficiency of a double sea kayak compare to a tandem canoe? A single sea kayak?

How much more necessary is a rudder on a double?

Is it at all feasible to paddle a double solo from the rear cockpit for light recreational paddling?

I'd build 4 or 5 singles, but I could never transport them. I'm leaning toward building a couple of doubles.