The laying of the North Sea mine barrage was not accomplished without very considerable delay, and many difficulties were encountered. It was originally antic.i.p.ated that the barrage would be completed in the spring of 1918, but owing to various defects in both British and United States mines which made themselves apparent when the operations commenced, due partly to the great depth of water as well as to other causes, a delay of several months took place; and, even when near completion, the barrage was not so effective as many had hoped in spite of the great expenditure of labour and material involved. I have not the figures of the number of submarines that the barrage is thought to have accounted for, but it was known to be disappointing.

FLARES In the late summer of 1917 flares were experimented with; they were intended to be used from kite balloons with the object of sighting submarines when on the surface at night. Previously searchlights in destroyers had been used for this purpose. The flares were not much used, however, from kite balloons owing to lack of opportunity, but trials which were carried out with flares from patrol craft, such as trawlers and drifters, demonstrated that they would be of value from these vessels, and when the Folkestone-Grisnez minefield was laid in November and December, 1917, it was apparent that the flares would be of use in forcing submarines to dive at night into the minefield to escape detection on the surface and attack by gunfire.

Manufacture on a large scale was therefore commenced, and during 1918 the flares were in constant use across the Straits of Dover.

ELECTRICAL SUBMARINE DETECTOR The existence of this very valuable device was due to the work of certain distinguished scientists, and experiments were carried out during 1917. It was brought to perfection in the late autumn, and orders were given to fit it in certain localities. Some difficulty was experienced in obtaining the necessary material, but the work was well in hand by the end of the year, and quickly proved its value.

SUBMARINE AGAINST SUBMARINE Prior to the year 1917 the only areas in which our own submarines operated against enemy vessels of the same type was in the North Sea, or occasionally in the vicinity of the Hebrides. Grand Fleet submarines were used in the northern areas during 1916, and Harwich submarines operated farther south, but the number of underwater craft available was insufficient for any extended method of attack. Early in 1917, when our mercantile losses were very heavy, some submarines were withdrawn from the Harwich and Humber districts and formed into a flotilla off the coast of Ireland for this form of operation. Some risk had to be accepted in thus reducing our submarine strength in southern waters. At the same time some Grand Fleet submarines were organized into a watching patrol in the area off the Shetland Islands, through which enemy submarines were expected to pa.s.s. The watch off the Horn Reef and in the Heligoland Bight, which had previously been in force, was also maintained.

A little later the submarine flotilla off the Irish coast was strengthened, and a regular patrol inst.i.tuted near the North Channel between Ireland and Scotland. The next step was the withdrawal of some "C" Cla.s.s submarines from coastal work on our east coast to work in the area between England and Holland near the North Hinder Lightship, a locality much frequented by enemy submarines on pa.s.sage. Still later some submarines were attached to the Portsmouth Command, where, working under Sir Stanley Colville, they had some striking successes; others went to the Dover Command. The latter were fitted with occulting lights on top of the conning-tower, and were moored at night to buoys in the Dover Net Barrage, in places where enemy submarines were likely to pa.s.s, in order that they might have a chance of torpedoing them. A division of submarines was also sent to Gibraltar, to operate against enemy cruiser submarines working in that vicinity or near the Canaries. Successes against enemy submarines were also obtained in the latter locality.

Finally, the arrival of some United States submarines enabled the areas in which this form of attack was in force to be still further extended, after the American personnel had been trained to this form of warfare. There was a great increase in the number of enemy submarines sunk by this method of attack during 1917 as compared with previous years; the number of vessels sunk does not, however, convey a complete appreciation of the effect of this form of anti-submarine warfare. The great value of it lay in the feeling of insecurity that it bred in the minds of the enemy submarine commanders. The moral effect of the constant apprehension that one is being "stalked" is considerable. Indeed, the combination of our aircraft and our submarine patrols led to our vessels reporting, regretfully, that it was very seldom that German submarines were found on the surface in daylight, and towards the end of 1917 quite a large proportion of the attacks on merchant ships took place at night.

The work for our own vessels was very arduous indeed. It was only on rare occasions that it was possible to bring off a successful attack on a submarine that had been sighted, the low underwater speed of submarines making it difficult to get into position when the enemy was only sighted at short range, which was naturally usually the case.

In order to obviate this difficulty directions were given in 1917 to design a special type of submarine for this form of warfare, and I believe that the first vessel was completed by the autumn of 1918.

This account of the development of anti-submarine measures during 1917 would not be complete without mention of the work of the Trade Division of the Staff, of which Captain Richard Webb, C.B., was the Director until September.

This Division was either partly or wholly responsible for:

(1) The great increase in the rapidity of placing the armaments on board merchant ships.

(2) The establishment of schools of instruction for captains and officers of the Mercantile Marine.

This training scheme was begun at Chatham Barracks in February, 1917, by Commander E.L.B. Lockyer, acting under Captain Webb, and later was extended to Portsmouth, Cardiff and Greenock. Its success was so marked, and its benefit in a.s.sisting officers to handle their ships in the manner best calculated to save them from submarine attack so great, that the Admiralty was continually being pressed by shipowners and by the officers of the Mercantile Marine to extend the instruction to more and more ports. This was done so far as possible, our princ.i.p.al difficulty being to provide officers capable of giving the instruction required.

(3) The provision of wireless plant and operators to the Mercantile Marine. This was another matter taken up with energy during 1917, and with excellent results.

(4) The drilling of guns crews for the merchant ships. Men were invited to go through a course of drill, and large numbers responded and were instructed at the Royal Naval Depot at the Crystal Palace.

All these matters were additional to the important work upon which the Trade Division was constantly employed, which included all blockade questions, the routeing of merchant ships, examination of ships, etc.

In addition to the instructional anti-submarine course for masters and officers, gunnery courses for cadets and apprentices were started at Portsmouth, Chatham and Devonport. A system of visits to ships by officer instructors for the purpose of affording instruction and for inspection, as well as for the purpose of lecturing, was inst.i.tuted, and arrangements were made for giving instruction in signalling. Some idea of the work carried out will be gathered from the following figures showing the instructional work carried out during the year 1917:

Masters 1,929 Officers 2,149 Number of cadets and apprentices pa.s.sed through the gunnery course 543 Number of merchant seamen trained in gunnery at the Crystal Palace 3,964 Number of ships visited by officer instructors 6,927 Numbers attending these lectures: Masters 1,361 Officers 5,921 Number of officers and men instructed in signalling 10,487 The keenness shown by officers and men of the merchant service contributed in a marked degree to the success of the courses inst.i.tuted; just one example may be given. I visited the Royal Naval Depot at the Crystal Palace early in 1918, and amongst other most interesting scenes witnessed a large number of men of the merchant service at gun drill. I questioned several of them as to their experiences, and many of the men had had their ships torpedoed under them three, four or five times. Amongst the gun crews was a steward who had been through this experience four times. On my asking why he, as a steward, should be going through the gunnery course, he replied that he hoped that by so doing he might stand a chance of getting his own back by a.s.sisting to sink a submarine.

The knowledge which I possessed of the measures introduced during the year 1917 to combat the German submarine warfare, and the continual increase in the efficiency of the anti-submarine work which I knew would result from increased production of anti-submarine vessels and weapons, led me in February, 1918, to state that in my opinion the submarine menace would be "held" by the autumn of the year 1918. The remark, which was made at what I understood to be a private gathering, was given very wide publicity, and was criticized at the time, but it was fulfilled, as the figures will indicate.

CHAPTER IV

THE INTRODUCTION OF THE CONVOY SYSTEM The question of the introduction of convoys for the protection of merchant ships was under consideration at various times during the war. The system had been employed during the old wars and had proved its value in the case of attack by vessels on the surface, and it was natural that thoughts should be directed towards its reintroduction when the submarine campaign developed. There is one inherent disadvantage in this system which cannot be overcome, although it can be mitigated by careful organization, viz. the delay involved. Delay means, of course, a loss of carrying-power, and when tonnage is already short any proposal which must reduce its efficiency has to be very carefully examined. The delay of the convoy system is due to two causes, (a) because the speed of the convoy must necessarily be fixed by the speed of the slowest ship, and (b) the fact that the arrival of a large number of ships at one time may cause congestion and consequent delay at the port of unloading. However, if additional safety is given there is compensation for this delay when the risk is great. One danger of a convoy system under modern conditions should be mentioned, viz. the increased risk from attack by mines. If ships are sailing singly a minefield will in all probability sink only one vessel-the first ship entering it. The fate of that ship reveals the presence of the field, and with adequate organization it is improbable that other vessels will be sunk in the same field. In the case of a convoy encountering a minefield, as in the case of a fleet, several ships may be sunk practically simultaneously.

During the year 1916, whilst I was still in command of the Grand Fleet, suggestions as to convoys had been forwarded to the Admiralty for the better protection of the ocean trade against attack by surface vessels; but it was pointed out to me that the number of cruisers available for escort work was entirely insufficient, and that, consequently, the suggestions could not be adopted. This objection was one that could only be overcome by removing some of the faster merchant ships from the trade routes and arming them. To this course there was the objection that we were already-that is before the intensive campaign began-very short of shipping.

Shortly after my taking up the post of First Sea Lord at the Admiralty, at the end of 1916, the question was discussed once more. At that time the danger of attack by enemy raiders on shipping in the North Atlantic was small; the protection needed was against attack by submarines, and the dangerous area commenced some 300-400 miles from the British Islands. It was known that unrestricted submarine warfare was about to commence, and that this would mean that shipping would usually be subjected to torpedo attack from submarines when in a submerged condition. Against this form of attack the gun armament of cruisers or armed merchant ships was practically useless, and, however powerfully armed, ships of this type were themselves in peril of being torpedoed. Small vessels of shallow draught, possessing high speed, offered the only practicable form of protection. Shallow draught was necessary in order that the protecting vessels should themselves be comparatively immune from successful torpedo fire, and speed was essential for offensive operations against the submarines.

Convoy sailing was, as has been stated, the recognized method of trade protection in the old wars, and this was a strong argument in favour of its adoption in the late war. It should, however, be clearly understood that the conditions had entirely changed. Convoy sailing for the protection of merchant ships against torpedo attack by submarines was quite a different matter from such a system as a preventive against attack by surface vessels and involved far greater difficulties. In the days of sailing ships especially, accurate station keeping was not very necessary, and the ships comprising the convoy sailed in loose order and covered a considerable area of water. On a strange vessel, also a sailing vessel, being sighted, the protecting frigate or frigates would proceed to investigate her character, whilst the ships composing the convoy closed in towards one another or steered a course that would take them out of danger.

In the circ.u.mstances with which we were dealing in 1917 the requirements were quite otherwise. It was essential for the protection of the convoy that the ships should keep close and accurate station and should be able to manoeuvre by signal. Close station was enjoined by the necessity of reducing the area covered by the convoy; accurate station was required to ensure safety from collision and freedom of manoeuvre. It will be realized that a convoy comprising twenty to thirty vessels occupies considerable s.p.a.ce, even when steaming in the usual formation of four, five or six columns. Since the number of destroyers or sloops that could be provided for screening the convoy from torpedo attack by submarines was bound to be very limited under any conditions, it was essential that the columns of ships should be as short as possible; in other words, that the ships should follow one another at close intervals, so that the destroyers on each side of the convoy should be able as far as possible to guard it from attack by submarines working from the flank, and that they should be able with great rapidity to counter-attack a submarine with depth charges should a periscope be sighted for a brief moment above the surface, or the track of a torpedo be seen. In fact, it was necessary, if the protection of a convoy was to be real protection, that the ships composing the convoy should be handled in a manner that approached the handling of battleships in a squadron. The diagram on p. 107 shows an ideal convoy with six destroyers protecting it, disposed in the manner ordered at the start of the convoy system.

[Ill.u.s.tration on Page 107, With Caption 'Diagram Ill.u.s.trating a Convoy of 25 Merchant Ships, With an Escort of 6 Destroyers Zigzagging at High Speed for Protection. the Convoy Shown in Close Order and on Its Normal Course.']

[Ill.u.s.tration on Page 108 Shows, According to Its Caption, 'Typical Convoy and Escort of 10 Trawlers in the Early Days of Convoy.']

How far this ideal was attainable was a matter of doubt. Prior to 1917 our experience of merchant ships sailing in company had been confined to troop transports. These vessels were well officered and well manned, carried experienced engine-room staffs, were capable of attaining moderate speeds, and were generally not comparable to ordinary cargo vessels, many of which were of very slow speed, and possessed a large proportion of officers and men of limited sea experience, owing to the very considerable personnel of the Mercantile Marine which had joined the Royal Naval Reserve and was serving in the Fleet or in patrol craft. Moreover, even the troop transports had not crossed the submarine zone in company, but had been escorted independently; and many naval officers who had been in charge of convoys, when questioned, were not convinced that sailing in convoy under the conditions mentioned above was a feasible proposition, nor, moreover, were the masters of the transports.

In February, 1917, in order to investigate this aspect of the question, a conference took place between the Naval Staff and the masters of cargo steamers which were lying in the London docks. The masters were asked their opinion as to how far their ships could be depended on to keep station in a convoy of 12 to 20 vessels. They expressed a unanimous opinion that it was not practicable to keep station under the conditions mentioned, the difficulty being due to two causes: (1) the inexperience of their deck officers owing to so many of them having been taken for the Royal Naval Reserve, and (2) the inexperience of their engineers, combined with the impossibility of obtaining delicate adjustments of speed by reason of the absence of suitable engine-room telegraphs and the poor quality of much of the coal used. When pressed as to the greatest number of ships that could be expected to manoeuvre together in safety, the masters of these cargo steamers, all experienced seamen, gave it as their opinion that two or possibly three was the maximum number. The opinions thus expressed were confirmed later by other masters of merchant ships who were consulted on the subject. It is to the eternal credit of the British Merchant Marine, which rendered service of absolutely inestimable value to the Empire throughout the war, that when put to the test by the adoption of the convoy system, officers and men proved that they could achieve far more than they themselves had considered possible. At the same time it should be recognized how severe a strain was imposed on officers, particularly the masters, of vessels sailing in convoy.

The matter was kept constantly under review. In February, 1917, the Germans commenced unrestricted submarine warfare against merchant ships of all nationalities, and as a consequence our shipping losses, as well as those of Allied and neutral countries, began to mount steadily each succeeding month. The effect of this new phase of submarine warfare is best ill.u.s.trated by a few figures.

During the last four months of 1916 the gross tonnage lost by submarine attack alone gave the following monthly average: British, 121,500; Allies, 59,500; neutrals, 87,500; total, 268,500.

In the first four months of 1917 the figures became, in round numbers:

British. Allies. Neutrals. Total.

January 104,000 62,000 116,000 282,000 February 256,000 77,000 131,000 464,000 March 283,000 74,000 149,000 506,000 April 513,000 133,000 185,000 831,000 (The United States entered the war on April 6, 1917.)

NOTE.-In neither case is the loss of fishing craft included.

It will be realized that, since the losses towards the end of 1916 were such as to give just cause for considerable anxiety, the later figures made it clear that some method of counteracting the submarines must be found and found quickly if the Allied cause was to be saved from disaster.

None of the anti-submarine measures that had been under consideration or trial since the formation of the Anti-Submarine Division of the Naval Staff in December, 1916, could by any possibility mature for some months, since time was necessary for the production of vessels and more or less complicated materiel, and in these circ.u.mstances the only step that could be taken was that of giving a trial to the convoy system for the ocean trade, although the time was by no means yet ripe for effective use of the system, by reason of the shortage of destroyers, sloops and cruisers, which was still most acute, although the situation was improving slowly month by month as new vessels were completed.

Prior to this date we had already had some experience of convoys as a protection against submarine attack. The coal trade of France had been brought under convoy in March, 1917. The trade between Scandinavia and North Sea ports was also organized in convoys in April of the same year, this trade having since December, 1916, been carried out on a system of "protected sailings." It is true that these convoys were always very much scattered, particularly the Scandinavian convoy, which was composed largely of neutral vessels and therefore presented exceptional difficulties in the matter of organization and handling. The number of destroyers which could be spared for screening the convoys was also very small. The protection afforded was therefore more apparent than real, but even so the results had been very good in reducing the losses by submarine attack. The protection of the vessels employed in the French coal trade was entrusted very largely to trawlers, as the ships composing the convoy were mostly slow, so that in this case more screening vessels were available, although they were not so efficient, being themselves of slow speed.

For the introduction of a system of convoy which would protect merchant ships as far as their port of discharge in the United Kingdom, there were two requirements: (a) A sufficient number of convoying cruisers or armed merchant ships, whose role would be that of bringing the ships comprising the convoy to some selected rendezvous outside the zone of submarine activity, where it would be met by the flotilla of small vessels which would protect the convoy through the submarine area. It was essential that the ships of the convoy should arrive at this rendezvous as an organized unit, well practised in station-keeping by day, and at night, with the ships darkened, and that the vessels should be capable also of zigzagging together and of carrying out such necessary movements as alterations of course, etc.; otherwise the convoy could not be safely escorted through the danger area. (b) The other essential was the presence of the escorting flotilla in sufficient strength.

It has been mentioned that there was an insufficient number of vessels available for use as convoying cruisers. It was estimated that about fifty cruisers or armed merchant ships would be required for this service if the homeward-bound trade to the British Isles alone was considered. An additional twelve vessels would be necessary to deal with the outward-bound trade. At the time only eighteen vessels were available, and these could only be obtained by denuding the North Atlantic entirely of cruisers.

The situation in regard to destroyers or other fast vessels presented equal difficulties. Early in February, 1917, we had available for general convoy or patrol work only fourteen destroyers stationed at Devonport and twelve sloops at Queenstown, and owing to repairs and the necessity of resting officers and men periodically, only a proportion of these were available at any one time. A number of these vessels were required to escort troop transports through the submarine danger zone. During the month of February six sloops were diverted from their proper work of minesweeping in the North Sea and added to the patrol force at Queenstown, and eight destroyers were taken from the Grand Fleet and sent to southern waters for patrol and escort duty. There were obvious objections to this weakening of the North Sea forces, but it was necessary in the circ.u.mstances to ignore them.

This total of forty destroyers and sloops represented the whole available force at the end of February. Simultaneously a careful investigation showed that for the inst.i.tution of a system of convoy and escort for homeward-bound Atlantic trade alone to the United Kingdom, our requirements would be eighty-one destroyers or sloops and forty-eight trawlers (the latter vessels being only suitable for escorting the slow 6-7-knot ships of the trade from Gibraltar to the United Kingdom). For the outward Atlantic trade from the United Kingdom our estimated requirements were forty-four additional destroyers or sloops.

The deficiency in suitable vessels of this cla.s.s is best shown by the following table, which reveals the destroyer position at different periods during the year 1917:

-------------------------------------------------------------------- Mediterranean.

----------------------------------------------------------------+ Pembroke. | -------------------------------------------------------------+ | Queenstown. | | ---------------------------------------------------------+ | | Bunerana. | | | ------------------------------------------------------+ | | | North Channel. | | | | ---------------------------------------------------+ | | | | Scapa and Invergordon. | | | | | ------------------------------------------------+ | | | | | The Tyne. | | | | | | ---------------------------------------------+ | | | | | | The Humber. | | | | | | | ------------------------------------------+ | | | | | | | Lowestoft. | | | | | | | | ---------------------------------------+ | | | | | | | | The Nore. | | | | | | | | | ------------------------------------+ | | | | | | | | | Portsmouth. | | | | | | | | | | ---------------------------------+ | | | | | | | | | | Devonport. | | | | | | | | | | | ------------------------------+ | | | | | | | | | | | Dover. | | | | | | | | | | | | ---------------------------+ | | | | | | | | | | | | Harwich Fleet. | | | | | | | | | | | | | ------------------------+ | | | | | | | | | | | | | Grand Fleet. | | | | | | | | | | | | | | --------------------+---+--+--+--+--+--+--+--+--+--+--+--+---+--+--- January. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flotilla Leaders | 10| 2| 3| | | | | | | | | | | | | | | | | | | | | | | | | | | Modern destroyers | 97|45|18|14|13| | | | | | | | | |29 |[A]| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Destroyers of River | | | | | | | | | | | | | | | cla.s.s and earlier | | | | | | | | | | | | | | | construction | | |11| 6|16| 9| | 9|11|15| 4| | | | 8 | | | | | | | | | | | | | | | P boats | | 2| 5| | 4|10| 4| 1| | | | | | | --------------------+---+--+--+--+--+--+--+--+--+--+--+--+---+--+--- June. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flotilla Leaders | 10| 3| 4| | | | | | | | | | | | | | | | | | | | | | | | | | | Modern destroyers | 95|23|29|38|15| | | 5| | | | 4| 32| |29 |[A]| | | | | | | | | | | |[B]| | | | | | | | | | | | | | | | | Destroyers of River | | | | | | | | | | | | | | | cla.s.s and earlier | | | | | | | | | | | | | | | construction | | |10| 5|16| 7| |29| 1|11| 4| | | | 8 | | | | | | | | | | | | | | | P boats | | 2| 6| | 8| 9| 4| 1| | | | | | 5| --------------------+---+--+--+--+--+--+--+--+--+--+--+--+---+--+--- November. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Flotilla Leaders | 11| 4| 6| | | | | | | | | | | | | | | | | | | | | | | | | | | Modern destroyers |101|24|26|37| 9| | | 4| | | |29| 35| |32 |[A]| | | | | | | | | | | |[B]| | | | | | | | | | | | | | | | | Destroyers of River | | | | | | | | | | | | | | | cla.s.s and earlier | | | | | | | | | | | | | | | construction | | |10| 4| 8|12| 2|30| |11| 4| | | | 8 | | | | | | | | | | | | | | | P boats | | 2| 6| |31| | | 1| | | | | |10| --------------------+---+--+--+--+--+--+--+--+--+--+--+--+---+--+--- [Footnote A: Includes destroyers detached for protection work in other commands.]

[Footnote B: Includes United States destroyers.]

There was the possible alternative of bringing only a small portion of the trade under convoy by taking all the available fast small craft from patrol duty and utilizing them to escort this portion of the trade, but it was felt that as this would leave the whole of the remaining trade entirely without protection, and no fast patrol craft would be on the trade routes to pick up the crews of any merchant ships that might be sunk by submarines, the step was not justified.

The next point for consideration was the possibility of obtaining destroyers or sloops from other sources with which to increase the forces for trade protection. The only commands on which it was possible to draw further were the Grand Fleet, the Harwich and Dover forces, the destroyers of old types working on the East Coast, or the destroyers and "P" boats protecting our cross-Channel communications west of the Dover Command.

It was out of the question to reduce the Harwich or Dover flotillas materially, as we were already running the gravest risks from the inadequacy of these forces to deal with enemy destroyers and submarines operating in southern waters from Zeebrugge or from German ports, and in addition the Harwich Force furnished the sole protection for the weekly convoy running between the Thames and Dutch ports, besides being much required for reconnaissance and offensive operations in the Heligoland Bight so far as it could be spared for this purpose. However, the emergency was such that destroyers were taken from Harwich, as the force obtained new vessels of a faster and more powerful type. The destroyers on the East Coast and in the Portsmouth Command were already inadequate to afford proper protection to the trade and the cross-Channel communications, as evidenced by our losses. Here again, however, in order to meet the very serious situation, some destroyers were eventually transferred to Devonport from Portsmouth, but at the expense of still less protection and fewer opportunities for offensive action against submarines. There remained only the Grand Fleet destroyers on which we could draw yet further. It had always been held that the Grand Fleet required a total force of one hundred destroyers and ten flotilla leaders for the double purpose of screening the ships from submarine attack when at sea and of countering the enemy's destroyers and attacking his heavy ships with torpedo fire in a fleet action. We had gradually built the destroyer force of the Grand Fleet up to this figure by the early spring of 1917, although, of course, it fell far short of requirements in earlier months. It was well known to us that the High Sea Fleet would be accompanied by at least eight flotillas, or eighty-eight destroyers, when proceeding to sea at its selected moment, and it was quite probable that the number might be much higher, as many more vessels were available. At our average moment, even with a nominal force of one hundred destroyers and ten flotilla leaders, we could not expect that more than seventy destroyers and eight leaders would be present with the Fleet, since, in addition to those absent refitting, a considerable number were always engaged on trade protection or anti-submarine work in northern waters which could not join up in time to accompany the Fleet to sea. When the Scandinavian convoy was started in April, 1917, one flotilla leader and six destroyers from the Grand Fleet were used for its protection; other vessels in northern waters also depended on Grand Fleet destroyers for protection. Any further transference, therefore, of destroyers from the Grand Fleet to southern waters for trade protection was a highly dangerous expedient, involving increased risk from submarine attack on the heavy ships in the event of the Fleet proceeding to sea, as well as disadvantages in a Fleet action. The necessity, however, was so great that the risk had to be faced, and for some months of 1917 from eight to twelve Grand Fleet destroyers were used for trade protection in the Atlantic, princ.i.p.ally from Irish ports, in addition to those protecting trade in the North Sea.

It is interesting to note the number of persons who claim to have been the first to urge the Admiralty to adopt convoys as a method of protecting merchant ships against submarine attack. The claimants for this distinction are not confined to Great Britain; the great majority of them are people without any knowledge of the sea and naval matters, certainly none of them possessed any knowledge of the number of vessels needed to afford protection to the ships under convoy, nor of the vessels which we could produce for the purpose at the time.