04/01 Thu. United States Naval Operating Facility, Grondal, Greenland,  
           is established.  
           Naval Air Station, Patuxent River, Md., is established. 
04/03 Sat.  Japanese naval vessel sunk:  
             Submarine chaser No. 13, by submarine PICKEREL (SS-177),   
              off Japan,  
              43 d. 03' N., 141 d. 58' E. 
04/05 Mon.  Japanese submarine sunk:  
             RO-34, by destroyer O'BANNON (DD-450),  
              Solomon Islands area,  
              08 d. 15' S., 158 d. 58' E. 
04/07 Wed. Submarine TROUT (SS-202) lays mines near Sarawak, Borneo.  
            Japanese aircraft make heavy strike against United States  
           naval vessels near Tulagi, Solomon Islands.  
            United States naval vessel sunk, Tulagi, Solomon Islands:  
             Destroyer AARON WARD (DD-483) and oiler KANAWHA (AO-1), by  
              horizontal bombers.  
            United States naval vessel damaged, Tulagi, Solomon Islands:  
             Cargo ship ADHARA (AK-71) and oiler TAPPAHANNOCK (AO-43),  
              by dive bombers. 
04/09 Fri. Rank of Commodore, United States Navy, is reestablished.  
            Japanese naval vessel sunk:  
             Destroyer ISONAMI, by submarine TAUTOG, (SS-199),  
              off Celebes,  
              05 d. 26' S., 123 d. 04' E. 
04/10 Sat.  United States naval vessel sunk:  
             Submarine TRITON (SS-201), Pacific Ocean area, reported as  
              presumed lost. 
04/15 Thu. Carrier YORKTOWN (CV-10) is commissioned at Newport News,  
           Va.; this vessel is named fro carrier YORKTOWN (CV-5), sunk 7  
           June, 1942, after the Battle of Midway.  
            Italian submarine sunk:  
             Archimede, by naval land-based aircraft, (VP-83),  
              off coast of Brazil,  
              03 d. 23' S., 30 d. 28' W. 
04/17 Sat.  German submarine sunk:  
             U-175, by Coast Guard cutter SPENCER (PG-36),  
              North Atlantic area,  
              48 d. 50' N., 21 d. 21' W. 
04/18 Sun. Admiral Yamamoto, Commander in Chief Japanese Combined Fleet,  
           is killed when his aircraft if shot down by Army aircraft. 
04/19 Mon. Submarine SCORPION (SS-278) lays mines off Kashima Nada,  
           Japan. 
04/20 Tue. Submarine RUNNER (SS-275) lays mines near Hong Kong. 
04/21 Wed. Submarine STINGRAY (SS-186) lays mines near Wenchow, China. 
04/22 Thu.  Japanese aircraft bomb airfield at Funafuti, Ellice Islands.  
             United States naval vessel sunk:  
              Submarine GRENADIER (SS-210), by enemy air attack and  
               scuttling, Straits of Malacca. 
04/23 Fri.  Japanese naval vessel sunk:  
             Patrol boat NO. 39, by submarine SEAWOLF (SS-197),  
              off Formosa,  
              23 d. 45' N., 122 d. 45' E. 
04/26 Mon. Task group of 3 cruiser and 6 destroyers (Rear Adm. C. H.  
           McMorris) bombards Japanese installations at Attu, Aleutian  
           Islands.  
           United States Naval Station, Mers el Kebir, Morocco, is  
           established. 
04/27 Tue.  German submarine sunk:  
             U-174, by naval land-based aircraft (VB-125),  
              North Atlantic area,  
              43 d. 35' N., 56 d. 18' W. 
04/29 Thu. Submarine GATO (SS-212) lands coast watchers at Teop Island,  
           Solomon Islands, and evacuates missionaries. 
04/30 Fri. Submarine GUDGEON (SS-211) lands personnel and equipment on  
           Panay, P. I.  
           Submarine SNOOK (ss-279) lays mines off Saddle Island, China.  
           United States Atlantic Fleet turns over responsibility for  
           convoys between Halifax and United Kingdom to British and  
           Canadian naval forces.