U-boat Archive - Admiralty CB 4051 - History of U-boat Policy

COPY No.

This book is invariably to be kept locked up when not in use and is not to be taken outside the ship or establishment for which it it issued without the express permission of the Commanding Officer

C.B. 4501

HISTORY

U-BOAT POLICY

1939-1945

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FEBRUARY

1946

iii

CONTENTS

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		Page.
	Introduction	1

SECTION I. 1939-1940


Date.	Title of Paragraph.	No. of Para.
25.08.39	Minelaying by U-Boats	1
29.08.39	Total Number of U-Boats	2
7.09.39	Operations against Merchant Shipping	3
15.09.39	U-Boat Operations in the North Sea	4
20.09.39	Use of Small U-Boats	5
20.09.39	U-Boats in the Atlantic	6
22.09.39	Methods of Attack by U-Boats	7
23.09.39	Lifting of Restrictions on U-Boat Targets	8
25.09.39	U-Boat Losses	9
10.10.39	U-Boat Building Programme	10
10.10.39	Blockade of England	11
13.10.39	Conduct of the U-Boat War	12
16.10.39	Attacks on Merchant and Passenger Shipping	13
17.10.39	North Sea and Baltic	14
29.10.39	Enemy Tankers	15
1.11.19	Conduct of the U-Boat War	16
10.11.39	Conduct of the U-Boat War	17
11.39	U-Boat Operations	18
6.01.40	Long Range U-Boats	19
26.01.40	Merchant Shipping	20
2.02.40	DOENITZ's Views on U-Boat Policy	21
9.02.40	U-Boats in Mediterranean--Italy's Reaction	22
23.02.40	Restrictions of Operations	23
26.03.40	Mediterranean Operations	24
26.04.40	Training Policy	25
4.06.40	The U-Boat Programme	26
12.06.40	Report by DOENITZ on U-Boat Losses	27
18.06.40	Atlantic Bases	28
13.08.40	RAEDER and HITLER in Conference	29
7.09.40	Summary of U-Boat Operations	30
20.09.40	U-Boat Supply Ships	31
28.09.40	U-Boat Building	32
14.11.40	Operational Objectives	33
3.12.40	Air Support for U-Boats	34
27.12.40	Long Term Building Policy	35
8.40	One Year of U-Boat Warfare	36

SECTION II. 1941

7.02.41	Co-operation with G.A.F.	37
27.02.41	U-Boat Successes	38
4.03.41	Control of Naval Air Operations	39
18.03.41	U-Boats for Rumania	40
12.04.41	Italian U-Boats	41
20.04.41	Change of Operational Area	42
20.04.41	U-Boat Numbers	43
20.04.41	U-Boats in the Mediterranean	44
28.04.41	DOENITZ's Views on Situation in U-Boat War	45
2.05.41	Difficulty in Locating Enemy Convoys	46
7.05.41	Offensive by Italian U-Boats	47
8.05.41	Difficulties in Locating Convoys	48
6.06.41	U-Boat Figures	49
16.06.41	DOENITZ's Views on U-Boat Operations in the Mediterranean	50
12.06.41	Use of Dakar as a U-Boat Base	51
18.06.41	Use of Dakar as a U-Boat Base	52
21.06.41	Withdrawal of Italian U-Boats from the Atlantic	53
26.06.41	U-Boat Figures	54
10.07.41	Effect of American Occupation of Iceland	55
21.07.41	Use of Torpedoes as Mines	56
22.07.41	DOENITZ's Views on Policy	57
25.07.41	Output of U-Boats Inadequate	58
31.07.41	Russia	59
7.41	U-Boat Construction	60
1.08.41	South Atlantic U-Boats	61
6.08.41	Italian U-Boats in Mediterranean	62
22.08.41	Need for Concentration of U-Boat Forces	63
22.08.41	Sending German U-Boats to Mediterranean	64
8.41	Successes and Prospects of the U-Boat War	65
2.09.41	Co-operation between U-Boats and G.A.F.	66
17.09.41	More U-Boats Necessary	67
19.09.41	Arctic U-Boats	68
30.09.41	U-Boat Successes	69

(C57405) *2

SECTION II. 1941 - continued.

Date.	Title of Paragraph.	No. of Para.
13.10/41	U-Boats in the Arctic	70
22.10.41	South Atlantic U-boat Policy	71
1.11.41	U-Boat Figures	72
1.11.41	Arctic U-Boats	73
1.11.41	U-Boats as Convoy Escorts	74
3.11.41	Subsidiary Operations for U-Boats	75
5.11.41	Supply Base in Western Mediterranean	76
10.11.41	U-Boat Distribution	77
10.11.41	Experimental U-Boat Types	78
15.11.41	Arctic U-Boat Operations	79
26.11.41	More Effective U-Boats	80
29.11.41	U-Boats in the Mediterranean	81
5.12.41	Review of U-Boat Situation	82
5.12.41	U-Boats for the Black Sea	83
8.12.41	Northern Waters and Norway	84
10.12.41	Large U-Boats	85
11.12.41	Views on the Mediterranean Situation	86
12.12.41	Numbers of U-Boats for Mediterranean	87
12.12.41	Transport of U-Boats to Black Sea	88
19.12.41	U-Boats in the Atlantic	89
20.12.41	U-Boats in the Mediterranean	90
24.12.41	America	91
24.12.41	Withdrawal of U-Boats from the Atlantic	92
27.12.41	Report on U-Boats	93
29.12.41	U-Boat Operational Areas	94
30.12.41	Mediterranean U-Boats	95

SECTION III. 1942

2.01.42	Withdrawal of U-Boats from Gibraltar	96
3.01.42	German U-Boats in Mediterranean	97
22.01.42	Lack of Man Power	98
10.02.42	Operations in Northern Atlantic	99
11.02.42	Communication with Japan	100
11.02.42	Disposition of U-Boats	101
11.02.42	Intentions	102
11.02.42	U-Boats in American Area	102 (a) and (b)
9.03.42	U-Boats in Iceland Area	103
13.03.42	U-Boats in Northern Waters	103 (a)
15.03.42	U-boat War in American Area	104
17.03.42	Repair of U-Boats	105
26.03.42	Caribbean Sea	106
4.04.42	Intelligence from U-boats	107
16.03.42	U-Boat Position in American Area	107 (a) and (b)
13.04.42	U-Boats in Norwegian Area	108
13.04.42	U-Boat Position	109
23.04.42	U-Boat Attacks on PQ Convoys	110
3.05.42	Importance of U-Boats in the Atlantic	110 (a)
9.05.42	Central and South America	111
10.05.42	U-Boats in Northern Waters	112
5.06.42	U-Boat Operations against Brazil	113
7.06.42	U-Boat Operations against Brazil	114
9.06.42	U-Boat Operations against Brazil	115
12.06.42	U-Boat Situation	116
17.06.42	U-Boats in American Area	117
15.06.42	U-Boat Attacks on Brazilian Shipping	118
19.06.42	U-Boat Operations in Northern Waters	119
4.07.42	Enemy Air Supremacy	120
15.07.42	Increase of U-Boat Operational Capacity	121
7.08.42	U-Boats in South Atlantic	122
10.08.42	U-Boats in South Atlantic	123
11.08.42	U-Boats in South Atlantic	124
17.08.42	U-Boats in the Mediterranean	125
26.08.42	U-Boats in the Black Sea	126
28.08.42	U-Boat Losses to Date	127
4.09.42	Weapon Development in U-Boats	128
9.09.42	Lack of Air Co-operation with U-Boats	129
9.09.42	Allied Shipping Losses	130
22.09.42	German/Japanese Spheres of U-Boat Action	131
24.09.42	U-Boat Intentions	132
28.09.42	Conference on U-Boats	133
6.10.42	Increase in Operational U-Boats	134
13.10.42	U-Boat Operation in Indian Ocean	135
10.42	Analysis of Causes of Enemy Shipping Losses	136
18.11.42	Losses in the Mediterranean	137
19.11.42	Disposition and Intentions of U-Boats	138
27.11.42	Activity on African Supply Route	139
1.12.42	U-Boat Operation off South Africa	140
2.12.42	U-Boat Operation off South Africa	141
9.12.42	U-Boats for Northern Waters	142
23.12.41	Watch on Allied African Supplies	143
24.12.42	Disposition and Numbers	144
24.12.42	Walter U-boats	145
28.12.42	U-Boat Base in Far East	146

SECTION IV. 1943

Date.	Title of Paragraph.	No. of Para.
27.01.43	Planning and Construction of U-Boats	147
8.02.43	U-Boat Dispositions	148
8.02.43	Need for Reconnaissance	149
26.02.43	Difficulty in Locating Convoys	150
26.02.43	German U-Boats for Japan	151
4.04.43	U-Boat Support from Japan	152
11.04.43	New Construction	153
11.04.43	Serious U-Boat Losses	154
21.05.43	Review of First Quarter, 1943	155
31.05.43	Crisis in U-Boat War	156
15.07.43	Shortage of Workers for U-Boat Constructions	157
19.07.43	U-Boat Losses in Bay of Biscay	158
16.09.43	North Atlantic	159
10.12.43	Air Reconnaissance for U-Boats	160

SECTION V. 1944

1.01.44	Radar	161
10.01.44	North Atlantic	162
18.01.44	Disposition of U-Boats	163
2.44	Shortage of Aircraft for Atlantic Air Reconnaissance	164
26.02.44	Delay in New Types of U-Boats	165
20.03.44	Decrease in U-Boat Operations	166
12.04.44	Allied Aircraft Carriers in Northern Waters	167
4.05.44	Protection of Section Construction and Assembly of New U-Boats	168
24.04.44	Invasion Counter-Measures	169
5.07.44	Employment of U-Boats against Invasion	170
9.07.44	Employment of German Naval Personnel	171
12/07.44	U-Boat Force in Atlantic	172
21.07.44	Anti-Invasion Operations	173
29.07.44	Disposition of U-Boats after the Invasion	174
10.08.44	Deployment of U-Boats in Invasion Area	174 (a)
3.08.44	Withdrawal of U-Boats from the West	174 (b)
13.10.44	Dates for New Types of U-Boats	175
31.10.44	Norwegian Waters	176
3.12.44	U-Boats against Enemy Carriers	177
3.12.44	Hope of Successes with Schnorchel	178
1.10.44	U-Boat War, Situation and Prospects	179
11.11.44	Falling Strength of German Naval Forces	179 (a)

SECTION VI. 1945

1.45	Development of U-Boat War	180
3.01.45	Schnorchel U-Boats	181
17.01.45	Insufficient Air Reconnaissance for U-Boats	182
18.01.45	Operations with Schnorchel	183
21.01.45	Operations off Gibraltar -- Schnorchel Again	184
21.01.45	Fuel Shortage. Immobilisation of Big Ships	185
22.01.45	Proposal to Allocate U-Boat Personnel to Land Warfare	186
23.01.45	Danzig Bay--Anxiety	187
26.01.45	Worries about Loss of Silesia--U-Boat Production	188
28.01.45	U-Boat Operations	189
28.01.45	Fuel Oil Position	190
11.02.45	U-Boats off the English Coast	191
16.02.45	Prospects of the U-Boat War	192
17.02.45	Advantages of Schnorchel	193
17.02.45	DOENITZ still Optimistic	194
20.02.45	Baltic. Russian Advance threatens U-Boat Training	195
23.02.45	Defense of U-Boat Building Yard at Bremen--Anxiety	196
23.02.45	State of U-Boat Building and Repairs	197
24.02.45	Effect of Schnorchel on the U-Boat War	198
26.02.45	Serious Loss of U-Boats at Bremen	199
1.03.45	U-Boat Policy	200
2.03.45	Expectation of Results with New U-Boats	201
16.03.45	Disposition of U-Boats	202
28.03.45	DOENITZ's Views on Pre-War Building	203
8.04.45	Redisposition of U-Boats	204
10.04.45	Grave Losses of U-Boats through Air Raids	205

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(C57405) *3

APPENDIX A

	Date.
Table 1	22.11.39	Plans for U-Boat Building.
Table 2	1.11.40	Review of U-Boats in Commission since September, 1939.
Table 3	26.01.41	State of U-Boats.
Table 4	10.11.41	Disposition of Operational U-Boats.
Table 5	1941	Distribution of Operational U-Boats in 1941.
Table 6	11.02.42	U-Boat Numbers and Dispositions.
Table 7	40-42	U-Boat Building Programme, 1940-42.
Table 8	12.03.42	U-Boat New Construction Plan for 1942 and 1943.
Table 9	12.06.42	State of U-Boats.
Table 10	24.08.42	Survey of U-Boat Losses per Month from September, 1939-August, 1942.
Table 11	24.12.42	State of U-Boats.
Table 12-19 inclusive	1.04.42	Numbers of U-Boats of Different Types and Distribution of Operational U-Boats.
Table 20	1939-43	U-Boat Losses in the Baltic, Mediterranean and Atlantic. September, 1939-October, 1943.
Table 21	1939-1944	Estimated Monthly Sinkings of Allied Shipping by U-Boats, 1939-44.

APPENDIX B

List and particulars of Personalities mentioned in this Report.

APPENDIX C

List of Sources from which this Report has been Compiled.

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	I









	INTRODUCTION
	_______

	The following pages consist of extracts from the files of the U-Boat Division of the German Admiralty between 1939 and 1945. These extracts cover all available material on policy; in some cases the information is summarized or condensed.
	This book is therefore not a history, except to the extent that it indicates what was in the minds of those responsible for the conduct of U-Boat warfare; it forms a background for students of the U-Boat campaign, and for those engaged in historical research.

	_________________________


	February, 1946.

















	(C57405)

SECTION I

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SEPTEMBER, 1939--DECEMBER, 1940

25.08.39.	1. Minelaying by U-Boats
	Raeder stated that he was exploring the possibilities of minelaying around the ports used by shipping between England and France and the main ports on the west coast of England. He stressed the strength of the British anti-U-boat defences.

29.08.39.	2. Doenitz stated that of a total of 57 U-Boats, 49 were ready for operational duties.

7.09.39.	3. Operations against Merchant Shipping
	A discussion took place between Chief of Naval War Staff and Operations Division, on the future policy of U-Boat warfare in the Atlantic. It was stated that U-Boats available for Atlantic operations numbered 18. It was hoped that by October there would be 26.
	Shortly before the outbreak of war, the intention was that all large U-Boats should proceed to the Atlantic for operations against English merchant shipping as soon as war was declared. The "Prize Law" was to be observed. This would force the British to restrict their merchant shipping and would make then resort to the convoy system. It was decided to continue this type of warfare until the convoy system was fully introduced, when U-Boats would work in packs.
	U-Boats would be able to operate against British naval forces in port, only if those forces were driven out of their bases by air attack by the G.A.F.

15.09.39.	4. U-Boat Operations in the North Sea
	The main tasks allocated to U-Boats in the North Sea were:
	(a) Attacks on targets around British bases and sweeps made in conjunction with other forces in areas south-west and west of Norway.
	(b) Minelaying off the south, south-east and east coasts of England.
	(c) Attacks on merchant shipping in the Skagerrak.
	(d) Protection of German ore imports from Narvik.
	(e) Reconnaissance and attack on troop transports in the Channel.

20.09.39.	5. Use of Small U-Boats
	U-Boat Division of Naval Staff decided that, since large U-Boats were reserved solely for operations in the Atlantic, small U-Boats should be used against bases in the north-east of England, and in the area east of the Pentland Firth and the Herbrides.

20.09.39.	6. U-Boats in the Atlantic
	The Chief of Naval Staff stated that 21 U-Boats were already in the Atlantic when war with England broke out. For the time being, only four to five boats would be operating at one time. At the beginning of October, a large number, about 10 to 12, would again be operating. There would then be convoys proceeding from the Mediterranean to England and from Cape Town to England, which would offer promising targets.

22.09.39.	7. Methods of Attack by U-Boats
	U-Boats had been instructed to attack French naval and merchant ships only in self defence, French and English convoys only when encountered north of Brest, and to spare all passenger steamers. Complaints were made that U-Boats were having great difficulties in identifying these targets, especially at night.
	Permission to attack without warning had not been given in writing, but this practice was approved by the Naval War Staff. If a U-Boat commander sank a merchant ship without warning, it was entered in his log as though he had confused it with a naval vessel or auxiliary cruiser.
	An order, approved by Raeder, dated 21.09.39, had been issued to U-Boats in the Channel to attack all darkened ships without warning. Efforts were being made by Flag Officer, U-Boats to extend this order to other areas.
	F.O. U-Boats demanded, as a protection for his own U-Boats and to facilitate attacks on merchant shipping, that all merchant ships using W/T for S.O.S. and position signals should, after the preliminary warning to stop, be sunk without warning.

23.09.39.	8. Lifting of Restrictions on Targets for U-Boats
	At a meeting with Raeder, Hitler ordered that French ships were no longer to be spared, and he agreed to the demand of F.O. U-Boats that merchant ships using W/T for S.O.S. could be sunk without warning. All darkened ships in certain areas and all merchant ships recognized as belonging to the enemy could be attacked without warning.

25.09.39.	9. U-Boat Losses
	Naval Staff estimated that five U-Boats had been lost to date. These losses were considered to be high.

10.10.39.	10. U-Boat building Programme
	In a report signed v. Fischel, prepared by the German Naval Office for Hitler, it was stated that considerably more raw materials, man-power, and works capacity would be needed to carry out the increased U-Boat building programme.
	Its execution should take precedence over all other tasks and services. Requirements of raw materials were given. These must be kept up for the duration of the war.
	The following figures represented extra indispensable man-power:
	Ship and ships' engines construction 29,000 men.
	Torpedo and mining 60,000 men.
	Fine mechanical and optical instruments 5,000 men.
	Other jobs 35,000 men.
	Total for the most important work 120,000 men.

10.10.39.	11. Blockade of England
	Raeder told the Führer that U-Boats had been ordered to abstain no longer from sinking Scandinavian merchant ships along the Scandinavian coast.
	For political reasons, the Fuehrer declined the proposal to have U-Boats built in, or bought from Russia.
	Raeder's view was that the occupation of the Belgian coast would not help the U-Boat war. He pointed out the importance to the Navy for the U-Boat wa of bases on the Norwegian coast (Trondheim).
	Hitler would consider this point.

15.10.39.	12. Conduct of the U-Boat War
	In a memorandum, Raeder stated that at present the war on merchant ships was waged according to the following rules:
	(a) Unarmed enemy merchant ships sailing independently: stop, search, bring in; if this is impossible, sink.
	(b) Neutral merchant ships sailing independently with contraband for enemy powers: stop, search, bring in; if this is impossible, sink.
	(c) Enemy merchant ships in convoy, likewise neutral merchant ships in enemy convoy: sink without warning.
	(d) Troop transports: sink without warning.
	(e) All merchant ships which offer resistance to capture, or threaten German ships: sink without warning.

	12 (a). U-Boats were now entitled to sink without warning:
	(i) All identified armed enemy merchant ships.
	(ii) All darkened enemy and neutral craft in enemy coastal waters, which were acting suspiciously.
	(iii) All ships which were making use of their W/T when the U-Boat surfaced, or when captured.
	The following were also top be stopped and searched:
	(iv) All unarmed enemy merchant ships sailing independently.
	(v) All neutral merchant ships sailing independently, or in neutral convoy.

	12 (b). For the present, the following were excepted from a capture and sinking:
	(i) The merchant ships of friendly neutral states; Italy, Spain, Japan and Russia.
	(ii) Passenger steamers, and steamers which might carry a considerable number of passengers, even when sailing in enemy convoy.
	(iii) Neutral ships sailing independently without contraband. On account of the British Admiralty's instructions to merchant ships to ram all U-Boats, U-Boats should sink without warning all enemy merchant ships, wherever encountered. The British Admiralty had also announced their intention to arm all merchant ships.

16.10.39.	13. Attacks on Merchant and Passenger Shipping
	At a meeting between Raeder and Hitler, the Fuehrer approved:
	(a) The torpedoing without warning of all merchant ships identified with certainty as enemy vessels (British or French).
	(b) Passenger steamers in convoy could be torpedoed shortly after being warned. Raeder remarked that passenger steamers were already being torpedoed, if they were darkened.
	(c) The Italian, Russian, Spanish and Japanese Governments should be requested to declare that they would carry no contraband, otherwise they would be treated as other neutral nations. (This was being done).

	13 (a). Russians Offer a Base
	Raeder announced that the Russians had placed a base west of Murmansk, in which a repair ship would be stationed, at the disposal of Germany.

17.10.39.	14. North Sea and Baltic
	Operations Division, Naval Staff, ordered U-Boats in the North Sea and Baltic to cease attacks on merchant shipping, as generally the danger incurred while observing the "Prize Law" was considerable. Operations against convoys, troop transports, etc., however, were to continue, if these ships endangered the U-Boats. Armed merchant ships could be attacked without warning.
	On 17.10.39, an order was issued to U-Boats to attack all enemy merchant ships by whatever means. This order was justified by the danger of ramming, or other active resistance by enemy ships. Enemy ships were not first to be boarded, but to be sunk by torpedo. Action by gunfire was to be avoided.

29.10.39.	15. Enemy Tankers
	Enemy tankers particularly were to be singled out for U-Boat attack.

1.11.39.	16. Conduct of the U-Boat War
	A memorandum by Raeder stated that even passenger steamers, sailing darkened and in convoy, might be attacked without warning. He stated that the blockade of England should be declared, by which neutral ships, after previous notification to neutral States, might be torpedoed without warning. At a conference with C.-in-C., G.A.F., it was decided that merchant ships in convoy might also be attacked from the air without warning.

	16 (a). Blockade of England
	Raeder stated that the moment of declaring the blockade must depend upon the development of the political situation, and the time and nature of the Army's advance. If the Army contravened the neutrality of the neutral States, the Navy would chose that moment for further action.

	16 (b). U-Boat Construction Programme
	In Raeder's opinion, the U-Boat construction programme had not been pressed strongly by Hitler, because equipment and munitions for the Army had priority. With the present allocation of steel, metals and workers, the big programme could not be executed. Another investigation into this problem was promised for December, but pressure would be needed to carry this through. (See Appendix A, Table I - Plan for U-Boat Building.)

10.11.39.	17. Conduct of the U-Boat War
	At a meeting with Hitler, Raeder proposed the next step should be the sinking without warning of enemy passenger steamers which were heavily armed and were used as troop transports, and for carrying contraband. It was known that these steamers were armed. Hitler agreed, on condition that the names of the large steamers concerned were first to be made known, and if it could be announced that they had been converted to auxiliary cruisers and troop transports.
	Raeder proposed as a later step, the sinking without warning of neutral steamers known to be laden with contraband and whose port and time of departure and route had been established (e.g., Greek steamers). The proposal was to be considered in conjunction with change of policy by neutrals. Ships of friendly nations (Italy, Japan, Russia, Spain) should not be attacked.

	17 (a). Bases for U-Boats
	Intelligence and control centres were to be established in neutral ports.
	Hitler asked Raeder whether the Navy had any special wishes about bases on the Dutch and Belgian coasts. Raeder said that these bases lay too near English coastal waters and were therefore useless for U-Boats. If Den Helder were occupied, it could possibly be of use as a base

	for light forces. The occupation of the Belgian and northern French ports was only important in so far as the British troop transports would be forced further south and would thereby be exposed to attack by U-Boats and mines.

Nov. '39.	18. U-Boat Operations
	A report on the direction of U-boat warfare up till the end of November, 1939, issued after a discussion between F.O. U-Boats and the Naval War Staff, stated that during October and November, large U-Boats, over and above those on Atlantic service, carried out minelaying operations against the British coast, Scapa Flow, and the Norwegian coast. The small North Sea U-boats also carried out minelaying.
	Minelaying had been satisfactory, but the number of torpedo failures was considerable and because of this, much enemy merchant shipping had escaped destruction.
	N.I.D. Note. See Admiral Doenitz's Essay, page 9, para 22. N.I.D. 1.G.P. 10.
	Seven U-boats had been lost through enemy action (no dates given).
	The number of U-Boats was still too small for the U-Boat forces to be split up in order to attack the enemy in different parts of the world, with or without the co-operation of auxiliary cruisers. For the moment, U-Boats were to work as a compact unit.
	Further mining operations by large and small U-Boats around the coast of England were being planned.

	18 (a). Bases
	Attempts were being made to acquire U-Boat supply bases in neutral countries, and small tankers for U-Boats were being built to supply U-Boats at sea and thus increase their radius of action.

	18 (b). Operations
	Naval Staff stated that nothing would suit the English better than the comparatively small number of U-Boats at Germany's disposal should continue to be used in the same manner as they had been up to date. The enemy's defence, turn-round in ports, and assembly at distant "rendezvous" was working smoothly, and the losses thus incurred could be accepted by him. Conservative methods of waging war were to the advantage of the enemy. The use of U-Boats in English coastal waters had been expected by the enemy, and had therefore been ineffective. The element of surprise was needed to make operations successful, and therefore new tactics must be devised. Since the number of U-Boats was still too small they must operate only where they were likely to achieve success. The results of the last-war policy of attacking merchant shipping in convoy with single U-Boats showed that this did not afford much success and the policy of sending out several U-Boats to make concerted attack on a convoy had not achieved the success expected, because of the enemy's use of direction-finding by bearings, and owing to the fact that only a maximum of nine Atlantic U-Boats could be sent out on concerted attacks.
	Naval Staff concluded that for the moment, enemy merchant shipping could only be
	The plans for towing U-Boats by surface vessels (auxiliary cruisers, which could also act as supply ships) to far distant areas of operation, such as the east coast of Canada, Freetown, Cape Town, Aden, Persian Gulf, Colombo, were in the opinion of F.O. U-Boats, quite possible, and had been successfully tested. Naval Staff considered that if this method proved successful, the English would have to reform their anti-U-Boat measures completely.

1940

6.01.40.	19. Long Range U-Boats
	It was decided by Naval Staff to use long-range U-Boats. Co-operation with auxiliary cruisers was being planned by Operations Division, and operations in the tropics now came under consideration.

	Assmann's Views on U-Boat Policy
	The following is an extract from an undated comment by Operations Division Naval Staff, on the possibility of co-operation between auxiliary cruisers and U-Boats, and on "the attitude of the F.O. U-Boats in this respect." (The memorandum is signed by Fregatten Kapitän Assmann.)
	"The opinion was expressed that the war against England merchant shipping could be more effectively waged, if there were some change in the U-Boat policy. It was condemned as being too conservative, and it provoked too many successful counter-measures on the part of the English.

26.01.40.	20. Merchant Shipping
	At a meeting between Hitler and Raeder, Hitler agreed to the sinking of neutral ships without warning (friendly neutrals excepted), in certain areas round England, in which the sinking might be attributed to mines.

	20 (a). New Types of U-Boats
	The Aurol U-Boat, an experimental boat of 80 tons with an estimated submerged speed of 27 knots, would be ready for trials in the spring. Plans for a boat of 320 tons, with a submerged speed of 25 knots, were in hand.

	20 (b). Anti-detection
	It was hoped to protect U-Boats from location by an "Opanin" covering. Opanin was a bye-product from Buna. Practical experiments would be made in a few weeks with "U.11."

2.02.40.	21. Doenitz's Views on U-Boat Policy
	On 2.2.40, Doenitz criticised Assmann's views (see above under 6.1.40) as follows:
	He denied that the success of U-Boat attacks on convoys had been vitiated by the enemy's use of direction-finding, and denied that huge packs of U-Boats were needed for concerted attacks on convoys. He referred to the recent success of a concerted attack on a convoy by only three U-Boats, and insisted that the best use was being made of the U-Boats available. With the existing shortage of boats, the long-distance operations proposed for U-Boats would weaken the chances of effective "kills" in nearer waters. In January, apart from vessels sunk by mines laid by U-Boats, 37 enemy steamers had been sunk by torpedo.

9.02.40.	22. U-Boats in Mediterranean - Italy's Reaction
	The report of an interview between the German Naval Attaché, Rome, and the Chief of Italian Staff, Somigi, mentioned a refusal by Italy to allow German U-Boat supply ships, disguised as Italians, to operate in the Mediterranean. Even the presence of German U-Boat supply ships in the Mediterranean would involve Italy in political difficulties with England, which was considered undesirable.
	An undated document entitled "Considerations on U-Boat Operations in the Mediterranean" issued by the U-Boat Division of Naval Staff, disclosed that the policy pursued up till then had been to supply U-Boats on the west coast of Spain and in the Canary Islands, and to send them to operate in the western area of the Mediterranean. The intention was to surprise the enemy in the eastern Mediterranean, and for this