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Rear Admiral Heathcote S. Grant, Senior Officer, Gibraltar, to British Admiralty


No. N.613/N.78/52?

H.M. Dockyard, Gibraltar.

7th August 1917.  


          I have the honour to submit to their Lordships information a short general report of the situation at Gibraltar as far as it affects the Patrol of the Eastern and Western side of the Straits versus the Enemy submarines, and the escort of Convoy of Homeward-bound vessels as for as 9°30’ West, the danger zone for submarines as at present.

     2.   The Patrol force under my command is at present disposed to best advantage in defending the western approaches to the Straits as far as approximately 9°30’ West and according to the traffic routes in force. The British force is assisted in this at present by 4 French submarines and some of the French Trawlers belonging to the Moroccan Division.

     3.   It is imperative, in view of submarine activity, that a strong Patrol should be maintained.

      (a) Off and to the Westward of Spartel,1 the converging

           point of both Homeward bound and Outward bound ships

           trading in Mediterranean, North American trade, etc.

      (b) In the Straits for defending all traffic into the  

           Examination Anchorage at Gibraltar.

      (c) Between Cape Spartel and Carnero Point2 for any

           submarines attacking in the Straits.

      (d) Patrol off the Examination Anchorage and Commercial

           Harbour and entering the Examination Anchorage or

           Admiralty waters.

      (e) Patrol off the Coasts of Spain to the East of Straits

           and between Cape Palos and Oran, the crossing place at

           night of most of the Mediterranean traffic not bound

           to Northern points.

     4.   There is now, in addition to the absolutely necessary Patrols mentioned in paragraph 3, the escort of convoy to 9°30’ West approximately every 4 days. There are also a considerable number of vessels bound East, who on account of the value of cargo, etc., are ordered to be escorted to various Mediterranean ports.

     5.   It is most urgently brought to their Lordships notice that the Convoy escort must necessarily deplete the Patrols, which later are imperative to control the submarine activity. It is therefore submitted that the force under my command should be strengthened as soon as possible, otherwise a concerted attack on shipping not under Convoy during the absence of the greater part of Patrol may mean a considerable loss in valuable vessels.

     6.   There is now one area, Cape St. Mary3 to Cape Trafalgar, on which I am relying on the French Patrol having no sufficient Patrol vessels of my own. This area comprising as it does the important port of Heulva, should, it is considered, be patrolled by a comparatively strong force in lieu of a couple of Trawlers as at present.

     7.   The addition to the force under my command necessary to carry out efficiently the Convoy work without depleting the Patrol should consist of:-

      (a) Ocean Escort:- 7 Sloops or “Q” vessels. This will

           allow, at 4 day intervals of Convoy sailings, for the

           5th vessel returning in time for her next Convoy and

           also give a margin of one ship for defects or


      (b) Destroyer Escort for Convoy to and from Gibraltar:-

           At least 10 Destroyers, which would allow 6-8 with

           each Convoy according to its dimensions, and 2 for

           boiler cleaning, etc., in harbor.

     8.   The present Patrol Force should be strengthened as follows:-

6 Destroyers or Torpedo Boats capable of standing the winter weather, to increase the St. Vincent Patrol and extend its operations as far as Cape Trafalgar, especially as regards the protection of Huelva traffic.

     9.   Since writing the above, Admiralty telegram No. 176 has been received informing me of the probably arrival between this date and the 1st, October next of 22 American vessels, which it is considered will, on arrival on the Station just meet the additional requirements for Convoy and Patrol work.

     10.  The attached statement showing the employment of the Patrol vessels during the month of July is forwarded for information.4

I have the honour to be,


Your obedient Servant,

/s/ H.S. GRANT.


and Senior Officer.                    

Source Note: Cy, DNA, RG 45, Entry 517B.

Footnote 1: A promontory in Morocco, Cape Spartel marks the entrance to the Straits of Gibraltar.

Footnote 2: Punta Carnero, Spain, is the southernmost point of Gibraltar, marking the entrance to the Straits on the European side.

Footnote 3: Also known as Cabo de Santa Maria, this smooth curve of sandy beach is the southernmost point in Portugal.

Footnote 4: This attachment is no longer with the original document.