Les green01 is right. The "L" key should do it with the stock game and most mods.
If you navigate to your main game folder (Silent Hunter Wolves of the Pacific) you can print off the keyboard assignments with the following image files:
TMO should have a specific image file for
its own Keyboard assignments. Look in its "Documents" folder.
If you haven't found the stock game SH4 Manual, try the "Support" folder.