On a similar note, has anyone rigged up a workable hands-free hydration system for
use with their surfski (or decked kayak)? How do you keep the tube/mouthpiece near
your mouth? Where do you put the water bag? Benefits and disadvantages?

I've tried a few things for the mouthpiece. As for the clips that come with most
systems, I've tried both one and two, in combination with tape around the tube, but
never had much luck keeping the mouthpiece within reach. The tube needs to be
stiffened and held in place better. I experimented with a wedge-shaped piece of
foam. I carved a "trough" to accomodate the tube, and taped it in. Then I rigged up
a "necklace" to hold it near neck-level. This worked well, but I didn't like wearing the
necklace because it was a hassle to get on and off, and seemed like it could cause a
problem if I came out of/off of the boat. Then I tried velcroing the foam to my PFD.
This seemed better. With both foam solutions, the foam was semi-permanently
attached to the tube, and kind of hassle in terms of filling and cleaning the system.

Previously I'd only used the hydration with decked boats. I tried putting the bag both
in front of and behind me. It was a real hassle to run the tube up through the skirt,
clothes, PFD, etc. Recently I got a surfski and a Platypus PFD hydrator. The bag
holder attaches easily to the back of a PFD, and works fine. However, I'm not sure
what I'll do if I'm not wearing a PFD (when it's strapped to the deck for a race). Also,
the Platypus tube seems stiffer than my Camelback tube, and so far I've had good luck
using a clip and some tape around the tube to hold it near my mouth.