was mustered. Defense in these African waters was very effective and U-boat losses were cor- 
respondingly high.” 
During 1942 some 1573 ships had been sunk; the average was 131 per month. The Germans 
were now keeping an average of about 80 U-boats continually at sea out of their pool of 360. The 
Sonar-Asdic fitted escorts totalled about 800 oceangoing types. 82 U-boats, plus 20 Italian and 
16 Jap subs had been sunk, averaging 10 per month. 
Early in 1943 the general locality of surfaced U-boats which transmitted reconnaissance 
data by radio signals was detected from long distances by High Frequency Radio Direction 
Finders installed ashore in America and Britain as well as by equipment installed in escorts. 
Such localities were searched by land-based and escort carrier planes equipped with Radar, 
which was becoming increasingly effective since U-boat Radar intercept.receivers were unable 
to detect the surprisingly short waves employed. Radar contact was lost once the U-boat sub- 
merged (in about forty seconds) Planes parachuted several floating expendible Radio-Sono Buoys 
whose suspended underwater Sonar hydrophones could detect U-boat noises which activated its 
radio transmitter. Such transmissions, when received in the planes or nearby escorts, indicated 
the U-boat’s area which could then be swept by Sonar-Asdic fitted escorts for accurate location 
and attack. 
In the early summer of 1943 an average of about 120 U-boats were operating in the Atlantic. 
U-boat packs were frequently out-numbering the escorts by 2 to 1.. Two convoys traveling close 
together were attacked by about 40 U-boats which sank 20 ships. Another convoy of 33 ships pro- 
tected by 8 escorts was attacked by a pack of about 20 U-boats which sank 12 ships during the 
midnight hour. -The same pack reattacked the next night - but, none of the remaining 21 ships 
were lost, 24 individual U-boat attacks were frustrated, and at least 5 U-boats were sunk. The 
escorts had been augmented by about a score of the newly built destroyer escorts and a dozen 
baby flattop aircraft escort carriers. Planes were sinking U-boats and also frustrating their 
attacks by forcing them to submerge. Allied aircraft patrols commenced 24 hour daily coverage 
over the Bay of Biscay; this intensified offensive had the effect of keeping U-boats submerged 
while they were in transit to and from their French bases thereby decreasing the time they could 
remain at sea. During May, June, and July we sank 108 U-boats. The crisis, or turning point, 
in the “Battle of the Atlantic” was being enacted. 
Typical battles which ranged between the U-boats and our escort killer groups are exem- 
plified by the sinking of the U-233 by the “Baby - Flattop” USS CARD and the destroyers, USS 
THOMAS and USS BAKER, 
First contact with U-233 was made on 2 July when CARD aircraft sighted a swirl about two 
hundred miles off Halifax. Radio-Sono Buoys were dropped around the swirl and contact with the 
U-boat was maintained throughout the day, although the intermittent bad weather required the 
recalling of aircraft necessitating cessation of listening to the buoys on Several occasions. Two 
destroyer eScorts were called in and conducted a Sonar search in the area without results. Sonar 
conditions were very poor, and from 2 to 5 July bad weather prevented further aircraft search. 
On 5 July, CARD, BAKER, and THOMAS were still searching the area. The BAKER made 
Sonar contact and streamed her Foxers to avoid acoustic torpedoes from the U-boat. At 1913 
CARD dropped a load of depth charges. At 1920 BAKER made the second attack with depth 
charges which resulted in a huge geyser of water mixed with oil. 
At 1925 Sonar contact was regained. At 1931 the radar operator reported a large pip at 
twelve-hundred yards. Simultaneously, the bow of the U-boat broke the surface at a steep angle 
on the radar bearing. Accurate and heavy gunfire was opened at a range of twelve-hundred yards. 
BAKER, then passed ahead of the U-boat and fired her port K-guns, The charges straddled and 
detonated close aboard on both bows of the U-boat. Gunfire continued and at 1941 BAKER again 
passed close ahead of the U-boat and dropped a pattern of depth charges. At this time, some of 
the U-boat’s crew were observed in the water astern of the U-boat and others were abandoning 
ship. 
A- 2405 
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