If you think swimming is an unavoidable risk (you said your dog could survive a couple of days), you might want to think of some redundancy in your inflation device. You might consider 4 or 5 bicycle innertubes tied/duct taped together. They are relatively inexpensive,compact package, easily inflated with a quality small bicycle pump, and if you have a tool to remove the stem of the schrader valve, can be inflated by mouth to a certain extent. I originally thought of them as an improvised water carrier... cut off the valve and fill the tube, sling over shoulder... pretty nasty tasting but and option... regards Les