Cris, take the balloon. Then drop down to the spot when you get on top of the sandcrawler. You can't get it from the ground. If you're unsure of your speed, turn off sprint, or even hit / on number pad to toggle walking so you don't overshoot. I just turned and faced the wall of the sandcrawler and backpedaled slightly.
"Sir,we are beginning our search for these rumored 'underwater villages'.They will not stay hidden for long". -Battle Droid Commander OOM-9!