Jeesus H. Christ! Some idiot with a needle gun has been blasting rust off an old crew boat for three straight days. He's about forty feet from my desk -- like being inside a 55 gallon drum with that fool hammering on the outside...kind of explains why I'm not being very productive.
FYI, a needle gun is hand held device, containing about twenty boron rods that jitter back and forth, powered by compressed air. The reciprocating rods bust rust off steel plate and can be pretty effective if the plate is thick enough (over 1/4"), but are useless for thin plating since it just deflects away under the blows. That moron is using it on 1/8" deck plating. All the energy is dissipated as sound, while the rust remains. This could go on for days.