Question about symbols

[andylegate]

Okay, it's high time that I asked this:

In SH3 I've seen the following symbols and inturpet them as such:

Triangle: Aircraft
Square: Merchant or Civilian ship
Diamond: Warship
Circle: Sub.

Now in the US Navy, we use the following symbols:

Ships:
Circle = friendly
Diamond = hostile
Square = Unknown

Aircraft:
Upper half of circle = friendly
Upside down V = hostile
upper part of square = unknown

Subs:
Lower half of circle = friendly
V = hostile
lower half of square = unknown

Obivously SH3 does not use these to get it down to the nitty gritty. But I am confused about something.

A small cirlce on my map will indicate a sub. A LARGE square normally indicates a Large Convoy, but so does a Large circle! I used to think that the large circle convoy's were friendly or allies, yet I've seen these leaving the coast of England!! ???

Can anyone explain what is going on?

[Brag]

Large circles in SH3 GWX are convoys shawowed by U-boats

[bigboywooly]

Aye Brag is correct
The convoy has a uboat shadowing and radioing back position

[andylegate]

That makes sense (sorta!). Thanks for the help guys.