The second happy time was a phase in the Second Battle of the Atlantic during which Axis submarines attacked merchant shipping to the east and south-east of the United States. It lasted from January 1942 to about August of that year. German submariners named it the happy time or the golden time as defence measures were weak and disorganised, and the U-boats were able to inflict massive damage with little risk. During the second happy time, Axis submarines sank 609 ships totaling 3.1 million tons for the loss of only 22 U-boats. This was roughly one quarter of all shipping sunk by U-boats during the entire Second World War, and constituted by far the most serious defeat ever suffered by the US Navy.
When Hitler declared war against the United States on December 11, 1941, that country was in a fortunate position. Where the other combatants had already lost thousands of trained sailors and airmen, and were experiencing shortages of ships and aircraft, the USA was at full strength. America had had the opportunity to learn about modern naval warfare by observing the conflicts in the North Sea and the Mediterranean, and through a close relationship with the United Kingdom. The US Navy already gained significant experience countering U-boats in the Atlantic, particularly from April 1941 when President Roosevelt extended the 'Pan-American Security Zone' east almost as far as Iceland. The United States had massive manufacturing ability, including certainly the largest and possibly the most advanced electronics industry in the world. Finally, the USA had a favourable geographical position from a defensive point of view: the port of New York, for example, was 3000 miles to the west of the U-boat bases in Brittany.
U-boat commander Dönitz, however, saw the entry of the US into the war as a golden opportunity to strike heavy blows in the tonnage war. The German Navy no longer had its surface tankers in the North Atlantic to refuel submarines (these had been sunk by Allied forces after Ultra intelligence revealed their locations) and the standard Type VII U-boat had insufficient range to patrol off the coast of North America, so the only weapons Dönitz had to hand were the larger Type IX boats. These, however, were less maneuverable and slower to submerge, making them much more vulnerable than the Type VIIs, and few in number.
Immediately after war was declared with the United States, Dönitz began to implement operation Paukenschlag ("drumbeat"), requesting that 12 Type IX U-boats be made available for it. The Naval Staff in Berlin, however, insisted on retaining 6 of the precious Type IX boats for the Mediterranean theatre (where they could achieve little) and one of the remaining 6 encountered mechanical troubles. This left just 5 long-range submarines for the opening moves of the campaign.
Loaded with the maximum possible amounts of fuel, food and ammunition, the first of the 5 Type IXs left Lorient on 18 December 1941, the others following over the next few days. Each carried sealed orders to be opened after passing 20°W, and directing them to different parts of the North American coast. No charts or sailing directions were available: KLt. Reinhard Hardegen of U-123, for example, was provided with two tourist guides to New York, one of which contained a fold-out map of the harbour.
Each U-boat made routine signals on exiting the Bay of Biscay, which were picked up by the British Y service and plotted in Rodger Winn's London Submarine Tracking Room, which was then able to follow the progress of the Type IXs across the Atlantic, and cable an early warning to the Canadian Navy. Working on the slimmest of evidence, Winn correctly deduced the target area and passed a detailed warning to Admiral King in the USA of a "heavy concentration of U-boats off the North American seaboard", including the 5 boats already on station and fresh batches already in transit, 21 U-boats in all. Rear-Admiral Frank Leighton of the US Combined Operations and Intelligence Center then informed the responsible area commanders, but little or nothing was done.
The primary target area was the "North Atlantic Coastal Frontier", commanded by Rear-Admiral Adolphus Andrews and covering the area from Maine to North Carolina. Andrews had practically no modern forces to work with: on the water he commanded 7 Coast Guard cutters, 4 converted yachts, 3 1919-vintage patrol boats, 2 gunboats dating to 1905, and 4 wooden submarine chasers. About 100 aircraft were available, but these were short-range models only suitable for training. As a consequence of the traditionally antagonistic relationship between the US Navy and the Army Air Force, all larger aircraft remained under Air Force control, and in any case the Air Force was neither trained nor equipped for anti-submarine work.
Nevertheless, there was much that could have been be done. The lessons of the First Battle of the Atlantic were plain, and British experience in the first two years of World War II confirmed them: ships sailing in convoy—with or without escort— were far safer than ships sailing alone. Obvious standard routings should be avoided wherever possible; navigational markers, lighthouses, and other aids to the enemy should be removed, and a strict blackout enforced. None of this was attempted. Coastal shipping continued to sail along marked routes and burn normal steaming lights. On 12 January 1942 Admiral Andrews was warned that 3 to 4 U-boats were about to commence operations against coastal shipping, but refused to institute a convoy system on the grounds that this would only provide the U-boats with more targets.
For the 5 Type IX boats in the first wave of Operation Drumbeat, it was a bonanza. They cruised along the coast, safely submerged through the days, and surfacing at night to pick off merchant vessels outlined against the lights of cities and amusement parks. Hardegen in U-123 sank 7 ships totalling 46,744 tons before he ran out of torpedoes and returned to base, Kals in U-130 6 ships and 36,988 tons, Zap in U-66 5 ships of 33,456 tons, and Bleichrodt in U-109 4 ships of 27,651 tons. U-125 under a new captain on his first cruise sank only a single 6,666 ton vessel. (Captain Ulrich Folkers, though criticised by Dönitz, would later win the Knight's Cross.)
The tanker MS Pennsylvania Sun, torpedoed by U-571 on 15 July 1942..
Despite the urgent need for action, little was done to try to stop the sinkings. The USN was desperately short of anti-submarine vessels, partly because of President Roosevelt's 1941 decision to loan 50 obsolete World War I destroyers to Britan in exchange for foreign bases, partly because the massive new naval construction programme had prioritised other types, and partly because the destroyers that remained were assigned to trans-Atlantic convoy escort and not under Andrews' command. Nevertheless, there were no less than 25 Atlantic Convoy Escort Command Destroyers on the US east coast at the time of the first attacks, including 7 at anchor in New York Harbour, yet when U-123 sank the 9,500 ton Norwegian tanker Norness within sight of Long Island in the early hours of the 14th of January none were dispatched to investigate, with the result that U-123 was free to sink the 6,700 ton British tanker Coimbra off Sandy Hook on the following night before proceeding south towards New Jersey. By this time there were 13 destroyers idle in New York Harbour, yet still none were employed to deal with the immediate threat, and over the following nights U-123 was presented with a succession of easy targets, most of them burning navigation lamps.
When the first wave U-boats returned to port in early February, Dönitz wrote that the commander "had such an abundance of opportunities for attack that he could not by any means utilise them all: there were times when there were up to ten ships in sight, sailing with all lights burning on peacetime courses".
By this time, the second wave of Type IX U-boats had arrived in American waters, and the third wave had reached its patrol area off the oil ports of the Caribbean. With such easy pickings available and all Type IX U-boats already committed, Dönitz allowed the short-range Type VII U-boats to take part as well. This required extraordinary measures: cramming every conceivable space with provisions, filling the fresh water tanks with diesel oil, and crossing the Atlantic at very low speed on a single engine to conserve fuel.
In the United States there was still no concerted response to the attacks. Overall responsibility rested with Admiral King, but King was far more interested in the Pacific Theatre—obsessed with the Pacific, according to his critics. Admiral Andrews' North Atlantic Coastal Frontier was expanded to take in South Carolina and renamed the Eastern Sea Frontier, but most of the ships and aircraft needed remained under the command of the C-in-C Atlantic Fleet, who was often at sea and unavailable to make decisions. Rodger Wynn's detailed weekly U-boat situation reports from the Submarine Tracking Room in London were available but ignored.
Popular alarm at the sinkings was dealt with by a combination of secrecy and misleading propaganda. The Navy confidently announced that many of the U-boats would "never enjoy the return portion of their voyage" but that, unfortunately, details of the sunken U-boats could not be made public lest the information aid the enemy. All citizens who had witnessed the sinking of a U-boat were asked to help keep the secrets safe. In fact, the real secret was that there was no secret—through the summer and the first half of autumn 1942, there were no U-boat sinkings at all.
Astonishingly, there was still no attempt to organise convoys, and still no blackout of coastal towns to make ships more difficult to see.