Rob I've been watching this thread for replies since it appeared a week ago. I'm kinda surprised there haven't been any.

But then the Mirage drive is something of an anomaly; marriage between a recumbent bicycle and a watercraft.

Might I suggest you contact DIllon Majoros at CLC for his perspective on your intent? It was either Dlllon or John Harris who engineered adding a Mirage drive to the Waterlust expedition canoe that CLC was comissioned to design and prototype back in 2016.

I was motivated to acquire a Waterlust kit partly because of the novelty of the Mirage drive "upgrade". (I don't have one laying about I could take dimensions off of otherwise I'd offer to help!) DIllon is better acquainted with these things and of course he's much better versed on how best to go about figuring out the intricacies involved. His position with CLC ought to be advantageous in helping you once you decide on which CLC watercraft best fits both your needs as well as being suited to adding mods to accept a Mirage unit.

Rob,

I have a Shearwater 17 and a Hobie Tandem Island with Mirage drives, and I'm a mechanical engineer.  There's no way on God's Green Earth you can retrofit the Shearwater to accommodate a mirage drive.  I'm only 5'9" and 165 and there's not a lot of open space in that cockpit.  If you took the deck off all the way to the forward bulkhead you would weaken the overall structure.  Also, there's not a lot of leg room and you probably would not have the room for the forward stroke on the mirage drive before you hit the bulkhead.  Hobie has the mirage drive on open cockpit kayaks for a reason.  You will want to look at open cockpit kayaks or canoes to do a retro job.

However, the Shearwater paddles like a dream.  My kayaking buddy says it looks like I'm riding on a 2 inch cushion of air while he's padding a 17 ft plastic kayak pretty hard to keep up.  My Shearwater 17 weighs in at 42.5 pounds so car-topping is easy.  The build is pretty easy.  I highly recommend it.

ScottPM, you've elaborated on what I wasn't prepared to address directly - that the deck-to-bottom dimension on most (all decked?) kayaks likely precludes ergonomically retro-fitting a Mirage drive. 

I've put a Mirage drive in a Wood Duck 14 and I've also built a Shearwater 17. ScottPM is right, the Shearwater could not accommodate a Mirage drive. The Wood Duck 14 has a huge cockpit and I still had to cut six inches out of the front of the cockpit to make room for the pedals. A Wood Duck double would have been a better choice. One thing I noticed when using the Mirage drive is the large amount of drag it adds to the boat. Once I was paddling with the drive in (giving my legs a rest) whern I noticed I was headding into a patch of lilly pads. Not wanting them to get caught on the drive, I pulled the drive out and put in the plug for the hole. When I resumed paddling, I was surprised at how much easirer it was to paddle. Those fins add a lot of drag (felt like they doubled it) and they are always in the water so even when you use them so some of you leg effort goes into overcomming that drag in addition to moving the boat. I've used them to go across a lake and when I got back I was really tired. Did the same thing in my Shearwater and I felt like I could have paddles for hours more.

Hey all, 

I really appreciate all the input and suggestions. It certainly sounds like I just need to build a Shearwater simple and straightforward. That's what I'll do.

Thanks!

I'm thinking the idea of the pedal drive in Waterlust was to make it possible to "motor sail" with feet engaged in pumping the flippers and hands thus free to work the sail and rudder, no?  Otherwise, might there be some advantage to engage the feet in flippering and the hands in paddling?

.....Michael