There are "channels" through all of the minefields, usually, but you CANNOT rely upon the surface vessels to show you the way, since mines in SH4 can be set deep, below the surface vessels' keel, and you will see convoys routed right through the minefields. Open "Jap_Minefields.mis", and "Merge" it with something like "43a_Jap_Convoys.mis" (do NOT click the "Mark merged data as saveable" tick box, else you'll have a mess). Zoom in on the home islands, and you'll see all sorts of RGG routed right through the perimeter minefields. Granted, some are set to -75 to -20 (meters, mind you), with the express purpose of taking out a sub, but some aren't. I do not know if a minefield will simulate a submarine catching the cable, as seen in the movies, and having it pull down toward the sub or not. That might be interesting to find out... With fields such as those, unless "layered" shallower, the best course of action, if you are so inclined to attempt, is to surface, and go over them... Anyway, as in a lot of aspects of the game, mines are sometimes placed in areas that a "sane" skipper would never think to take his boat, and are therefore used as a deterrent... sort of like Duci's Evil Airplanes...
