On the water - lip balm, a granola bar if I haven't eaten it already, and possibly a bandana.  That's it.  Knife is on my belt.  PFD with whistle is on me.  Everything else is stowed in packs, with the exception of my map case which has IDs, permits, papers.

On a portage - same as above minus the PFD but with the possible addition of bug spray if it's a long, buggy portage and someone else doesn't want it.