No rain catcher? No cooking gear? Good luck.If they don't have a rain catcher and need to boil it, then the DC should be higher even though water itself is abundant, the materials to make it boil are not. The availability of water isn't what drives the difficulty, the ease of getting potable water is. Cooking gear might help boil water, but getting dry wood to start a fire is tough.The DC should be relatively low, possibly low enough that it's not even worth rolling. If the characters are properly equipped, primarily rain catchers, they will have no problem getting what they need.That said, the biggest issue with foraging in Chult is a potential lack of equipment to get potable water. That's why it's in the DMG, you're supposed to make a judgement call. The rules as published work fine - there's no hard rule on determining which DC to use.
