I integrate PSK items with my backpacking gear rather than lug around a discrete PSK, but I arrange things so that certain items (knife, whistle, basic FAK, etc) are on my body at all times. This is especially true when sea kayaking. When I kayak, I put a basic PSK, plus flares and other kayaking specific survival items in the pockets of my life vest so that they are on body when(please note "when'" not "if") I do a wet exit from the kayak. I always wear the vest when in the boat.

Sounds like a neat trip...Have fun!