I’ve got a Wenonah Argosy that I would like to use a Kayak paddle with. With my tandems, I use a 56" Explorer Plus, and it seems too long for the solo. Any rule of thumb for choosing a yak paddle?
sure
You definitely came to the right place.
Kayak stroke is about swinging paddle about it’s center.
So, take a stick, make sure it is dry, center it, do a stroke on both sides. The dry length plus an inch or two will give you the distance between paddle blades. Look at various paddles, feel the vibe. Once you figure out what you like, add blade length, that is your paddle length.
Or, you could try a whole bunch of paddles and go with what feels good.
Making your own is always an option as well.
Oh, welcome to the “double side” 
That’s a good idea.
What about blade shape? I presume it’s a higher angle stroke in a canoe, which means a wider blade?
Could also consider a GP that drives
my Wen-Vag UL very nicely with both high and low angle strokes depending on conditions. Great cruiser. Had it made a bit long (264cm) to clear gunnels on low angle strokes. Used a 10’ closet pole to get specs as prev poster. Carry a single blade to work small overgrown creeks. R
depends
Depends if you’re kneeling or sitting, depends on your height too. I’ve got an Argosy and I’m 6’ tall and sit and use a 230 but I paddle with a very vertical stroke that many don’t like. So you’ll need something longer if you’re as tall as I am, sit in the boat and want a lower stroke.
Bill H.
That’s good info
I’m 5’9" (on a good day)and also sit. I use the Argosy for day trips on local rivers and lakes. I have long monkey arms, however. What’s the down side of getting an adjustable length paddle?