Protecting oilers is part of protecting the fleet

Both navies were short of tankers, and the United States was arguably in a crippling position, but Japan's five oilers guarded by one destroyer were especially exposed. The two American oilers each had a destroyer, at least giving every tanker warning and a fighting chance against an isolated attacker. Line-ahead and box-like arrangements placed destroyers where their guns could cover several approaches. Those formations could not defeat every threat, but they show deliberate thought about protecting replenishment vessels. Fuel ships are central to carrier operations because losing them can collapse a fleet's ability to stay at sea and use its combat ships.