Until the reasonably priced small boat water makers, I didn't consider it prudent to carry food that required water to reconstitute it, a good idea. We'd buy a ton or so of canned goods and basic staples like rice and pasta whenever we were in a large city and we could cruise for 6 months to a year without inflation or buying anything but fresh food at the smaller, more expensive places.
We will still stock up on items that are outrageously priced on many of the islands (or just not available), like TP, select-a-size paper towels, Mayo, Ketchup and other condiments we like, but most canned goods and packaged foods available in the islands are OK, even if they are unfamiliar brands. A lot of American products are available on most islands in the Caribbean, but some, like Hellman's/Best Foods Mayo is way expensive.
I haven't seen the dehydrated foods down here, at all.
We've found the secret to eating well at sea is imagination. Lots of condiments and hot sauces can keep even 20+ days of eating canned food palatable. Since we can't count on catching fish as regularly as we could before, I always purchase a few whole canned chickens when available.