Opnav.
The Department had been notified from London Headquarters early in May that a large-type submarine had left Germany for American waters, and on May 15th, the British steamer Huntress reported that she had escaped a torpedo attack in latitude 34°-28' north, longitude 56°-09' west, about 1,000 miles east of Cape Hatteras. Four days later the Nyanza was attacked 300 miles from our coast; the Jonancy was gunned about 150 miles at sea, and on May 21st the British steamer Crenelia reported sighting a submarine.
This information was disseminated to all section bases, coast defense commanders and forces afloat; and in addition to the regular patrols, special sub-chaser detachments were organized, and ordered to proceed, upon the receipt of any "SOS" or "Allo" message, to the vessel attacked or in distress.
Comprehensive plans for defense, protection of shipping and combating the U-boats had been made long previously. Before we entered the war a general scheme had been adopted, a patrol force and naval districts organized. From that time on we had maintained a vigilant lookout for the German craft. A special Planning Board had been created in February, 1918, to study the situation afresh and recommend any additional measures that might be adopted for coast defense, and protection of shipping. These plans, approved March 6, placed coastwise shipping under the control of district commandants, district boundaries being, for this purpose, extended seaward and sharply defined. On May 4 a circular letter was sent to all ship-owners and masters, detailing the procedure they were to follow. Commandants were instructed to see that all routing preliminaries and shipping requirements and military and commercial arrangements on shore were made and thoroughly understood by all the interests concerned.
The morning of June 3rd, the order was issued to commandants, "Assume control of coastwise shipping and handle traffic in accordance therewith;" and the following warning was sent out:
Unmistakable evidence enemy submarine immediately off coast between Cape Hatteras and Block Island. Vessels not properly convoyed advised to make port until further directed.
A Coastwise Routing Office was organized in the Navy Department as a part of Naval Operations. Every naval district had its arrangement for routing and convoying traffic in and through its areas. The commandant made up the convoy, outlined its route, and provided escort through his territory, each district in succession relieving the previous escort. Thus naval protection was provided for shipping all along the coast.
Routing offices were also established at Halifax, Nova Scotia; at Havana, San Juan and all leading West Indian ports; and Tampico, Mexico—in fact, eventually at every Atlantic port where coastwise shipping was likely to originate.
Through the Naval Communication Service full information as to convoys, rendezvous and other details were sent in code. Each ship's master, before sailing, was required to go to the routing office and receive written instructions as to the route to be followed and areas to be avoided. He was given all the latest submarine information and was told of the signals and the location of each "speaking station."
