Chapter VIII
Independent Patrols in Distant Areas
Summer 1943

  1. Aircraft with radar everywhere.

  2. U-boat reaction.

  3. Recommendations for U-boats: When surprised, don't dive.

  4. The result as seen in the summer campaign.

  5. Radio intelligence comment.

  6. North American coast.

  7. Caribbean.

  8. South America.

  9. West Africa.

  10. Cape Town.


  1. Aircraft with radar everywhere.

    The summer of 1943 is the only period in U-boat traffic read here in which individual station patrols of distant coastal areas occupied the major strength of the U-boat navy. 1942 U-boat traffic, if and when read, should offer an interesting contrast, for in 1942 these distant patrols in American waters ran up some of the highest sinking records in the entire war. But in the summer of 1943 U-boats in distant waters encountered the same treatment that had just driven them out of the North Atlantic.

  2. U-boat reaction.

    On 17 July Command announced in Current Order Number 39 that:

    "Lately, especially in the Bay of Biscay, U-boats have been lost without any clue as to the cause, place, and time of their loss..."

    Special code groups were added to the short signal book for quick reporting of various kinds of aircraft attacks and of the subsequent condition of the U-boat. (Frequent use made these code groups valuable cribs.) On 21 July the situation in Biscay necessitated the following warning:

    "During cruise through Bay of Biscay the guiding thought of the Commander must be: Get the boat through safe and sound. Do not take any risks, thinking that you will get by, or helping to save time..." (Admonition message 1921/21 July 1943)

    Having gotten through Biscay alive and having escaped the refueling rendezvous traps, the U-boat which reached its distant area was met with the same thing all over again.

    Thater's (U-466) complaint, signaled from the area north of the Amazon mouth, was characteristics:


    "Air patrol as in Bay of Biscay. Radar day and night on 130 to 160 cm..." (0915/28 July 1943)

    There was no escape, for the return voyage meant carrier aircraft at the rendezvous' and once more the dangerous passage of Biscay.

  1. Recommendations for U-boats: When surprised, don't dive.

    The U-boat was urged to stay up and fight off the aircraft, training anti-aircraft guns on the plane's motors rather than on the better protected cockpit. Above all, the U-boat Commander was to keep his head and not dive at the last minute, thus putting himself completely at the mercy of the aircraft. It was necessary to send out admonition messages such as this:

    "During a surprise aircraft attack on a group of three submarines, one submarine made the mistake of submerging. It was bombed while diving. Its loss may be expected. The surface defense of the others was successful. Moral: When surprised, stay upstairs and shoot. Diving is death." (1246/20 July 1943)

    Submerged cruising became more and more mandatory, thus increasing the necessity for surfacing to charge batteries. Many messages were devoted to defining the favorable times and areas for battery charging and ventilation. The habits and tactics of antisubmarine aircraft were studied. Strict orders were issued about the maintenance of look-outs and the manning of anti-aircraft guns. The deck could no longer be used for "strength through joy" activities.

  2. The result as seen in the summer campaign.

    Forty-eight U-boats were sent out to occupy patrol areas off the North American, South American, and West African coasts. As has been previously stated, this scattering was a defensive as well as an offensive move. It failed in both respects. During four months in which they operated these forty-eight U-boats sank only 35 ships, no insignificant number to the Allies, but representing only a fraction of a ship sunk per U-boat engaged. The German cost was high: 13 submarines


    sunk in their operational areas (12 of them in American waters); at least eight more submarines never finished their homeward cruises; and five were forced to retire from their areas because of damages sustained.

  1. Radio intelligence comment.

    The period of U-boat dispersal was the one time between January 1943 and the end of the war when U-boat traffic gave Allied cryptanalysis the greatest consistent trouble. It was at least fortunate that the manner of U-boat warfare during this period was such as to offset in part the failure of ready decryption intelligence. In the various ways already mentioned, radio intelligence was able to furnish the essential information despite lags in reading, because of the correspondingly slower tempo of the U-boat war. Even with time delays of two to three weeks, one could still learn what U-boats were going where, before they could still learn what U-boats were going where, before they could arrive in their assigned areas. Decryption in relation to the refueling rendezvous' has already been discussed. The essential information for plotting was usually at hand. Once in its assigned area, of course, the U-boat observed a fairly general radio silence.

  2. North American coast.

    The North American coast continued to be an unproductive and dangerous patrol area. antisubmarine forces were, as in the spring, constantly in evidence except, as several Commander's reported, in the Gulf of Mexico. The defenses of the tanker ports of Texas were shrugged off as "inexperienced and slight." No shipping was sunk in this area, however. Along the Atlantic seaboard, hold-down tactics restricted U-boat movement, and convoy protection was strong and alert, ready at first contact to hunt the U-boat to destruction. The fact that only one U-boat was sunk off the North American coast was probably due more to U-boat caution than to antisubmarine failure. Only two ships were torpedoed, and one sunk during this period, indicating the inability of the U-boats to maneuver freely for attack. Five of the eleven U-boats which operated off our coast concluded their unsuccessful patrols by failing to survive their homeward voyage.


  1. Caribbean.

    Eight U-boats were scheduled to operate in the Caribbean Sea, only seven of which arrived there. Their efforts ended in almost total failure. In four months, only three ships are known to have been sunk, while three U-boats were sunk in the area. Moreover, only two of the remaining four U-boats arrived in France to give further reports of the aircraft and surface defenses which have been described, in transmissions from the Caribbean, as "strong and continuous," with extensive use being made of radar.

  2. South America.

    Again, as in the spring, the coast of South America, from Trinidad to southern Brazil, was the only really successful U-boat attack area. Twenty-five ships (including three Swedish ships), or better than 70% of all of the shipping sunk in the operations discussed in this chapter, were sunk by the 16 U-boats which appeared off the South American coast. From Commander's reports, the antisubmarine defenses seem to have been less regular, but very persistent once ships had been damaged or sunk. This would account for the higher shipping losses, and also for the high U-boat losses. Half of the 16 U-boats which operated were sunk, plus another on his way home.

  3. West Africa.

    From all aspects, operations off the west coast of Africa were dull. Possibly five ships were sunk by the 17 U-boats which infested the waters from Dakar to Lagos, and only one U-boat was sunk there. Aircraft and surface patrol was obviously expert in keeping U-boats out of firing range, and it was admitted by two skippers that they had left the Freetown area because chances for operations were poor. In the area north of Monrovia, one U-boat had encountered a "very expert DD," which used a "new kind of radar", which was possibly the same radar, beyond the range of Metox, which had been reported


    from the Caribbean in the spring. Command tried to nullify this threat by ordering U-boats to expose themselves to detection by radar to send only the most important of messages. Further difficulties arose when several U-boats seemed to leave their incentive, and had to be forced on to attack by Command. The situation continued to deteriorate, however, and by the end of August all boats had started for home, leaving this area free from U-boat danger throughout September.

  1. Cape Town.

    After May, there was no planned activity off Capetown, the only sinkings which occurred being the work of U-boats passing through, enroute operational areas in the Indian Ocean.


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Transcribed by Chuck Roberts for the Hyperwar foundation