When equipping your characters before setting out on an adventure, make sure you buy:
- The best weapons you can afford and that the GM will let you get away with using.*
- The best armour you can afford and that the GM will let you get away with using.**
- As many marginally useful odds and end as you can get with the few coins you have left over.
** Where "best" is defined as being the ones that prevent the most damage.
You never know when some insanely specific piece of equipment that nobody would think of buying normally might come in handy for some situation where the GM is trying to prevent you from doing something that you'd really rather like to try doing.
Qui-Gon and Obi-Wan have clearly done this. Why else would they be carrying underwater breathing gear? And clearly they must be special breathing gadgets that only work underwater - since they didn't use them when the Trade Federation tried to gas them in the waiting room on the ship earlier. "Gosh, the room is filling with poison gas, and I have breathing gear in my pocket - I know, I'll just hold my breath and see what happens!" The plot wouldn't be that stupid.
Jar Jar: Mesa shows you mesa underwater city.
Qui-Gon: Lead on!
Obi-Wan: How are we going to breathe underwater?
GM: I spent a week mapping out the surface of this planet...
Qui-Gon: Let me check my equipment list. Grappling hook, 50 feet of rope, a dozen blasters...
Qui-Gon: Here we go: underwater oxygen extraction apparatus - look, I've got two of them.
Obi-Wan: Right. Let's go.
GM: Wait a minute! Let me see your character sheet.
Qui-Gon: I had two gold left and they only cost one each...
GM: ... Fine. You go underwater.
GM: See this beautiful map? <scrunch scrunch>