The hook is a gift given to you by Manki in Quetzal, near the end of the story quest "Shipwrecked in Tucma!", and can't be received before then. After venturing to the airship docks in the East side ...

I went on a hike last weekend. Some of the trail was uphill, some was downhill, and I hiked along fine (if slowly). That’s not a surprise. But when I had to hop across a tiny stream, I had problems.