Yeah, tried to clone a sub tender to see if I could get rid of the "collision siren" (which doesn't sound anything like the real ones) but it wouldn't work for me.
What I was trying to do was get an effect like this;
with the player sub starting between the other two subs.
But if there's no simple way to clone a static (docked only, never moves) sub, this is really good enough for freeware;
BTW, if anyone is wondering, I keep zipped backups of the original SH4 1.4, and tested with all the default subs placed in various locations. This is in the original game - not a mod soup factor. No mods.