TV's Frink said:
Tyrphanax said:
Obi-Wan's lightsaber shorts out when he gets it wet in the swamp after escaping his landing craft. Lightsabers require special modifications, or else they don't work underwater, this is an established EU fact.
This is the reason he is running from the STAPs and why Qui-Gon has to rescue him. I feel like I've seen a deleted scene with this in it, but it may just be that the scene has been described in other sources.
While this might be a nice explanation to the question of why Obi is running for his life, and there may even be a deleted scene (not that I've heard of it)...this is still nowhere in the movie. Therefore, doesn't count.
You can actually see when Obi-wan is submerged here in this cutscene from the TPM video game.
It's also in the script as described here:
Three landing craft slowly descend through the cloud cover of the perpetually gray twilight side of the planet. One by one, the Federation warships land in the eerie swamp.
OBI-WAN's head emerges from the mud of a shallow lake. For in the background, the activities of the invasion force can be seen in the mist.
OBI-WAN takes several deep breaths, then dissapears again under the muddy swamp. Troop Transports (MTT's) emerge from the landing craft.
And:
In the distance, two STAPS burst out of the mist at high speed, chasing
OBI-WAN.
QUI-GON : I have no time for this now...
JAR JAR : Say what?
The two STAPS barrell down on OBI-WAN.
JAR JAR : (cont'd) Oh, nooooo! Weesa ganna....
QUI-GON throws JAR JAR into the mud.
QUI-GON : Stay down!
His head pops up.
JAR JAR : ...dieeee!
The two troops fire laser bolts at OBI-WAN. QUI-GON deflects the bolts back, and the STAPS blow up. One-two. OBI-WAN is exhausted and tries to catch his breath.
OBI-WAN : Sorry, Master, the water fried my weapon.
OBI-WAN pulls out his burnt laser sword handle. QUI-GON inspects it, as JAR JAR pulls himself out of the mud.
QUI-GON : You forgot to turn your power off again, didn't you?
OBI-WAN nods sheeplishly.
QUI-GON : (cont'd) It won't take long to recharge, but this is a lesson I hope you've learned, my young Padawan.
OBI-WAN : Yes, Master.
JAR JAR : Yousa sav-ed my again, hey?
OBI-WAN : What's this?
QUI-GON : A local. Let's go, before more of those droids show up.
JAR JAR : Mure? Mure did you spake??!?