I guess I"m with Drewfus... 2 tandems & a solo, rotate solo assignments, build solo skills, stick relatively close together as a group.  I've seen Kingfisher's 3-in-1 option work nicely but I wouldn't touch it in a canoe of lesser size than his 18 footer.  

Also, KF's citation of the adventure/fubar potential can work TWO different ways on group morale.  On one hand, please note Magic Paddler smiling contentedly with his feet propped-up as KF & Dede cheerfully chauffeur him about WCP like the King of Siam.  This is a case involving a well-tuned group with a generally constructive positive approach to the challenges & hardships of any given day.

ON THE OTHER HAND, sometimes personalities don't mesh so well.  Putting three persons in the tub together merely catalyzes underlying issues with group dynamics... especially when hardships arise.  My case in point involves this story of hardship:   (You need to Login or Register   Never, ever, ever should I have put my Type A wild man brother in the same canoe as my more laid-back & reflective buddy Tom who preferred to slow down & smell the roses, so to speak.  Bad choice... very, very bad!  Strangely enough, on that particular (first ever) trip to Quetico, the three of us consciously elected the three in a boat option while we TOWED a perfectly functional solo canoe (into which most of our packs, etc., were loaded).  Ultimately, we came to our senses after a few days, & put the wild man into the solo where he could have his "space" (& before he could kill Tom).  As a result, camp morale quickly soared.

Bottom line: group dynamics should be closely considered before selecting the 3-in-1 option.

Like I said, I'm with Drewfus on this one.

Jimbo   8-)