Visible crew/equipment: On the highway, after the Gornickes were unsuccessful at returning the laptop, when the RV takes the exit in the rear shot the crew's location set lights are reflected on the RV's surface. (00:58:00)
Visible crew/equipment: When everyone is singing their own song (except Robin Williams), the last shot of this scene shows the back of the RV. As the camera pans down, you can see several cars reflected in the window, one of which is the crew's truck with the camera crane erected above it. (00:18:35)
Visible crew/equipment: When the Gornickes and the Munros are eating outside at the RV park, you can see a crewmember reflected on the Gornicke bus.
Visible crew/equipment: After the State Trooper stops the Munros, when Gary and Larry speak to Bob the reflector screen is clearly reflected in Larry's eyeglasses. (01:31:50)
Visible crew/equipment: After Bob urges Alpine not to merge, when Carl flips Todd there is a huge straight edge shadow where they stand, however, there is absolutely nothing near the seated people that would cause such a shadow - only the crew's equipment. (Even more noticeable on fullscreen DVD.) (01:29:20)
Answer: In the world of "make believe", they used "movie magic" to zap the RV out of the water and on to dry land - with no mechanical issues resulting from being submerged. In the real world, someone called a tow truck - perhaps AAA - and the RV was pulled out of the water and it suffered water damage and needed some repairs. This movie was presented as being "real life." Bob left on a bicycle to "try to find help." Near the end of the movie, Carl said that the RV "spent two days under water and they had to fish it out." He didn't say who "they" were. A fishing pole would not be strong enough to reel in a large RV, so I think it is safe to conclude that a tow truck was used to pull the RV out of the lake.
KeyZOid
It should be noted that "fish it out" is a common phrase to mean pull or take out, especially after searching. When people use the term, they're never taking about using a fishing pole. But often when people post questions like this, they're asking for an in-film explanation in case they missed (or didn't understand) something. If no in-film explanation was given, a reasonable speculation can be given. You don't need to remind people the movie is a movie. If the in/film explanation is uncharacteristic to real life, then one can point out that in real life it wouldn't happen that way.
Bishop73
It was meant to be ironic.
KeyZOid
There was no irony, but this isn't the forum for irony anyways.
Bishop73
I guess I failed miserably... but wasn't the original question rhetorical?
KeyZOid