[bluesquids]

You can bungie a hand pump inside your yak under the cockpit center consul. It will be out of the way and you can forget about it, until the day comes you need it.
I used deck loops for attachments inside, with matching ones backing them on the outside.

Also, it's likely you'd have to jump in the water to pump it out, because you might be riding so low that water will rush in the hatch when you open it.