[edit]Aren't you concerned that the lines could tangle in some gear at the worst possible moment [/edit]

After I load my canoe, I carefully lay the bow/stern lines on top of the packs keeping them as taut as possible. Yes, there's always that chance they may get tangled if you have a lot of miscellaneous gear mounted, but tied to the bow/stern pulls you have zero chance of getting to them when you need them most.

Paddling open water I sometimes tie them off to bow/stern pulls, but in rivers/streams I want them readily accessible. The reason you use floating rope with no knots or loops in loose end is that if the rope sinks and hangs up on a submerged rock/branch, your lines can snag and turn you over.

I suppose if you were really worried about them snagging on gear, you could route them under gunnel's securing them with a small Velcro loop, or some type of little clip, enough to keep them in place but light enough you don't tip canoe when you deploy them.

I've never had a problem just leaving them laying taut on tops of packs, but I don't hang gear off my packs, so you should plan accordingly.