Vice Admiral William S. Sims, Commander, United States Naval Forces Operating in European Waters, to Admiral William S. Benson, Chief of Naval Operations
Date May 1st, 1918
Prepared by CS. Approved NCT Code 34 ADR. No. 7289.
7289. Admiralty informs me that information from reliable agents states that a submarine of Deut<s>chland type left Germany about nineteenth April to attack either American troop transports or ships carrying material from the States.
So far as known the German formed conclusions that:
First: Troop transports go from New York via Fire Island, Nantucket Shoals and Salle Island direct to Europe.
Second: Material transports go from Newport News to a point south of Bermuda and then to Azores and thence to destination.
It is thought that the submarine is taking a Northern route across Atlantic average speed five knots.
None of new class of cruising submarine ready for service.
Admiralty experience with Deutschland class establishes following conclusions:
They generally operate a long distance from shore and seldom in less than one hundred fathoms.
Their single hulls are very vulnerable to depth charge attack.
They rarely attack submerged.
There is but one known instance of attack against convoy and but two of torpedo attack against single vessels, one being unsuccessful.
They attack by gun fire almost exclusively.
The most effective type to oppose them is the submarine.
They shift their operating area as soon as presence of submarine is discovered.
Admiralty requests Admiral Grant be given copy of this cablegram.
Source Note: Cy, DNA, RG 45, Entry 517B.