Eric Zala (who played Belloq) having a plaster cast of his face made for the final "exploding Nazi head" sequence. They used the wrong kind of plaster, the kind with a heating agent mixed in, so his face was burning, and then they couldn't get it off because his eyebrows and eyelashes (!) were caught in the plaster! They tried a hacksaw and a hammer and chisel (!!!!) before finally calling 911 and going to the hospital -- oh, and letting Mom know what was up. Unreal! This same kid also played the Ratty Nepalese, the guy whose back is on fire in the Nepal pub scene, and he got singed in that, and the production nearly got shut down completely due to lack of fire safety! Also, Nat asked about how they got all the dialogue so correct, and get this -- when they started out there was no VHS or laserdisc available, so they wrote it all out from memory! In the car on the way home, we were most amazed at how these kids stuck with this project for so long, and with such (relatively) high-quality results...everybody might have played "Indiana Jones" back then in the yard, but only for a day or two, not 7 years!
The submarine, by the way, was used by the kids after Chris (Indiana Jones) spent 3 years talking to the guy who owned a WWII submarine moored in Mobile Bay in Alabama and convinced him to allow them to shoot there, much to the bemusement of the local tourists.