33. It is a common experience of the Naval as well as Merchant service that torpedo wakes are reported where none exist. Many reports are received of torpedoes barely missing ships. This was true in the Jutland Battle. The Captain on one Battleship said that he received numerous reports of torpedoes passing just ahead and just astern, nearly all of which he had reason to believe did not exist.
Streaks of suds, slicks, etc., are very deceiving and are easily mistaken for torpedo wakes, particularly when the danger of torpedoes is present. This accounts for many reports by passengers on liners and other merchant craft of seeing many torpedoes just miss their mark.
34. Submarine versus Submarine:
There has always been opposition to using submarines against submarines, principally on the grounds that the possibilities of their accomplishments would not be sufficiently great to justify the risk involved of mistaken identity and resulting damage to friends.
The Director of Anti-Submarine Warfare believes, however, that such operations promise well, and the experiment is now being tried with as many submarines as can be spared from the Grand Fleet. Some enemy submarines have been destroyed by this method, usually torpedoed. One valuable feature of this method lies in the fact that as long as our submarines are not so used, the enemy submarine is always perfectly safe in assuming that all submarines sighted are friends. If this certainty is removed the enemy will be forced to keep down more, and to take much greater precautions against detection. This is an advantage of no small account.
In addition to the possible offensive work that may be accomplished by our submarines on such duty, the plan furnishes us with more reliable information as to the limitations and capabilities of enemy vessels under the actual conditions existing in the areas in which they operate. Without this knowledge based on actual experience too much is left to conjecture which is liable to lead to a great deal of misdirected effort.
(Signed) Wm. S. Sims.