Milo, do you find that floating line without a sink tip only works in the main part of the bar where water is slow? It is not easy to get a spot there though. Each fly guy seems to claim a big space in between and if you go late, you will be forced to fish the faster water below or above the main bar. That may be the place to have sink tip or sinking line. The last time I went with full floating line on a weighted fly in the faster stretch, hook up was much slower than the guy below me with a sinking line. I thought my skill was the reason for the slower action. Then he tried my rod and he could not hook anything with the floating line in 10 minutes. He switched back to his own rod and started hooking fish right away. So perhaps sinking line or floating line with sink tip has its merit in the faster stretch of the run. But you are right though. A sinking line will get some fish foul hooked but a good % is in the mouth.
There is a lot of river where the water is SLOW, almost stagnant. The upper part of the bar just below the Mamquam is only one of those areas. Then comes a faster shallow stretch and then again a slow long stretch. Yes, it can get busy, but sooner or later you can squeeze in somewhere. The floating line works basically anywhere where some douchebags haven't waded out to their nuts and pushed the fish out.
Just ask Bryan Bronswyk. Last week he found a spot where no one had waded below him, and he was basically roll-casting ten feet in front of him and catching good numbers of fish where the rest of us were getting nothing.
If given the chance, pinks will hug the shore and travel or sulk in a foot or two of slow moving water. On Sunday, to prove my point, I waded out to be in line with others who were up to their waist in water and I started casting towards the shore with my floating line. I started catching fish right away because many of them were travelling BEHIND us. The expression on the faces of some of the people fishing around me was priceless. LOL!
Now if you have no choice but to fish the faster and deeper water, obviously you need a heavier tip and/or some extra weight added to the fly (type II-IV will do just fine almost anywhere on the Squamish). If your fly line is bouncing off or snagging the bottom, it is too heavy - period.
I have seen people fishing type 8, 11, even 14 below the Mamquam and frankly, those people hardly catch any fish legitimately. When their fish are not completely foul hooked (tail, back, fin, etc), they end up with the hook embedded in the outside corner of the mouth - flossed. Not much fun if you ask me. Ask any fly fisher who has figured this out. A pink salmon properly hooked will jump, splash and roll just like a trout or a coho. A snagged or flossed fish doesn't. They are little more than a dead weight in the current.