One of the reasons ships moved in battle line/squadrons was the difficulty of communications, especially after battle erupted and the area smogged over with cannon smoke. Maintaining a battle line prevented blue on blue damage and casualties.

As stated in other threads, when we do battle line squadron formations, all ships follow the lead ship at a specified range using the increments on the back of the combat ruler, the lead ship uses the the deck for the slowest ship in the formation. It works well and allows a single player the ability to control more ships, with less maneuver card confusion. The ships may break formation at any time, and then use their own decks.