Some phones, like iphones are very finicky when it comes to what's on the other end of the USB cable.
Solar is probably the best option. I've had friends use that along the BC coast which is not known for sun.
With the hand crank option you would likely be better off charging up a large capacity battery then using that to charge your devices.
I would take some dielectric grease or contact cleaner if you are in saltwater.
Heel and Pegpads™
Pull-Up Strap Handle Kit
URCHIN Portable Anchor
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