Well, there's 2' of difference! I have the 17' for long (4-6 week) tandem northern trips. There's no way the 15' would work for that. But then it'd be a bear to solo. So it depends on how long you want to go out, whether you want to solo, etc. etc., just like any other canoe.
That is kind of why I am asking. I did part of the Noatak 2 summers ago in a SOAR and did not hate it, but did not love it either. I'm going back but I want to go in a canoe this time. All of the fly in trips I have done have been in the 8-10 day range. My work schedule precludes anything longer. The 170 just seems like too much for that length of time/amount of gear and the 150 seems right on the edge of not being big enough. I was hoping someone would have something really great or really awful to say about one or the other to assist in my decision making.
I'd guess the 15S would be the ticket. Dan spent several weeks in his last year---he'd be the man. PakBoats hold a lot of stuff. I have a friend that solos a 17 when she has to, and it is greatly affected by wind. She's looking for something smaller.
I was on the Noatak a few years ago for four weeks. Our group had three different Pakboats--a 160, a 165, and a 170. Everyone managed to carry the gear and bear barrels they needed but the 170 was clearly the best for a trip of that length. My daughter and I, in a 165, did fine, but I sometimes envied the people in the 170. And yet I think the 165 would be plenty adequate for shorter trips and could be used as a solo because it's a narrower. The Ally 16.5 would be another option. It's a little lighter and a little stiffer. (Since that Noatak trip I've switched from PakCanoes to Allys.)
MReid: "I'd guess the 15S would be the ticket. Dan spent several weeks in his last year---he'd be the man. PakBoats hold a lot of stuff. I have a friend that solos a 17 when she has to, and it is greatly affected by wind. She's looking for something smaller. "
My error--for some reason I thought you were interested in a solo. I haven't paddled the 16.5, but the 17 would work fine. You don't have to fill it up (though I have)! It looks like the 16.5 is a little sleeker. I certainly wouldn't go less than 16. The 17 might have better resale value, as it's the northern trip workhorse.