I have a real newby question: Why are stuffing tubes no good for subs? My type IX sub has some really long tubes that are a really close tolerance with some heavy grease and have not leaked on the surface. Is the pressure a foot under water that much greater to push all that grease into the water tight compartment? If you've seen my other post, you'll see I'm up against a 20 year old re-engineer and rebuild on this great hull and I only want to do it once. I just received a sample copy of the Sub Committee Report and was suprised to see another modeler with a working design similar water tight compartment as mine. But he didn't show the drive shafts.