Well folders in swift water rescue are a no go. Even thou that Spydie folder was made with sailors in mind.
Not sure if it is still the case, but merchant sailors were subject to fines for wearing a fixed blade in a folder. This did not stop many of them, myself included, from carrying a fixed blade. I would take the sheath off my belt when in port and at some other times, and either put a folder in my pocket or put the whole sheath in my back pocket. The law, I believe, was put in place to prevent sailors from having something with which they could easily stab their shipmates. I don't see how it stopped them from stabbing each other with folders. So, the folders were made for those sailors who were following the law and not wearing or carrying fixed blades. Desiging a folder for a sailor, imo, is more of keeping with the law, rather than the practical conditions a sailor faces.
I would not want it to be my only knife, if I were kayaking, but I would like that Gerber hanging onto something about chest level. Seems like a nice practical blade to cut you out of trouble.
When I was at sea, I tended to carrying a high-carbon, fixed blade, and did not really do much to adapt it to the environment, except I used gun-bluing to prevent corrosion.