Can't turn it on, can't turn it off... Webster's GFO is a fantastic version to play like that though, especially with his plane "fix"...
Two points from his ReadMe:
- - Air patrols have been reduced but pilots will now be a little more accurate when they are attacking you
- - The SD antenna mast was made to raise and lower when ordered to
Good stuff, so you can "find" airplanes at times from periscope depth when you raise the antenna - sometimes, because of directionality, so don't depend upon it 100%. It's a tool, to be used with others. Just don't forget to lower it, since it does make a disturbance in the water like the periscope, and will be "seen". Kind of like "X marks the spot", the DD & planes know where to drop the boom-boom...