Why did the US Navy need to fully transfer the US Coast Guard from the Department of the Treasury into the Department of the Navy? How did the Navy actually use the USCG during World War II? Finally, how did the two branches view one another during the war? Thank you for any input or sources.
The Coast Guard has been involved in every conflict since its creation in 1915. While their primary focus has been and remains to be securing our borders they can be deployed in order to defend us interests. And example of this is Coast Guard cutters being deployed in Africa (I believe South Africa but i am not a 100% sure) to combat piracy and as well in the Caribbean on Islands like Aruba to combat drug smugglers.
To answer your original question though is the Coast Guard played a bigger role in world war two than people realize. They fully manned more than 350 naval vessels, along with many more being partially manned by joint coast guard/navy, these vessels include 76 LSTs (Landing Ships, tank), 21 cargo and attack cargo vessels, 75 frigates and 31 transport ships. This doesn’t include us navy vessels which were partially manned by members of the Coast Guard. They also played a large role in port security and anti espionage efforts. This was very important for maintaining the US coastal security as it was not unheard of for a U-boat to be spotted off the United States Coast. They would also see combat in all theaters as well. An example of a Coast Guard ship seeing combat would be that of the cutter Muskeget, which was serving as a weather ship in the Atlantic, and was sunk by a U-boat resulting in all men aboard being killed.
However arguably their most important role was operating landing crafts during amphibious assaults. They played a major role in the invasion of North Africa, Sicily/Italy, Normandy, and the entire Pacific campaign. In fact this was arguably one of the more dangerous jobs a Coast Guardsmen could receive for duty. Signalmen First Class Douglas A. Munroe was one of these men. At the battle of Guadalcanal he is credited with saving many Marines swerving to attract Japanese fire to protect troops still making it to shore. He returned fire and was able to distract many Japanese soldiers and became their main mortar and machine gun target. He would be mortally wounded and later died. He is credited with saving countless lives in the battle. After his death he would be awarded the Medal Of Honor and still remains the only Guardsmen to have received the highest military honor.
They are many more things that these men, and women too, did during the second world war. I hope my answer has helped you learn a little bit more about the Coast Guard!
If there is any spelling mistakes i apologize i am currently using my phone. My sources are below.
https://m.usni.org/magazines/navalhistory/2016-10/coast-guards-world-war-ii-crucible
https://www.nps.gov/parkhistory/online_books/wapa/extContent/wapa/coast_guard/cg1.htm
The Coast Guard transferred from the Department of Treasury to the Department of the Navy on November 1, 1941, you will notice this is before the official entry of the US into World War II. This is because the Coast Guard was already assuming more military responsibilities, most notably the Greenland Patrol.
Greenland is a Danish territory that had the world's main source of cryolite, a substance used in the manufacture of aluminum. When the Germans invaded Denmark, the US worked a deal with the Danish ambassador to the US, setting up a consulate on Greenland and providing weapons for the defense of the cryolite mine. 14 Coast Guardsmen where officially discharged from US service and became part of the security team guarding the mine. The Danes also gave the US permission to build airbases on Greenland, as well as defend Greenland with its military assets. This allowed US-built planes to fly across to Europe, where they were turned over to the Allies. During this time, the Coast Guard was surveying the coast of Greenland, relaying weather information, reporting icebergs, escorting American convoys through ice, and occasionally performing search and rescue for torpedoed ships. It was during one search that the USCGC Modoc (WPG 46) actually stumbled into Bismarck under attack by planes from HMS Victorious. Luckily her colors were recognized as US and she was not fired upon.
The USS Greer incident, where a German U-boat fired upon a US destroyer, sparked President Roosevelt to issue a shoot-on-sight order. In a fireside chat on September 11, 1941, Roosevelt laid down his expectation that the presence of German vessels was itself and act of aggression, and would be treated as such. "In the waters which we deem necessary for our defense American naval vessels and American planes will no longer wait until Axis submarines lurking under the water, or Axis raiders on the surface of the sea, strike their deadly blow-first."
Around the same time as the Greer incident, the Greenland Patrol received a report of a suspicious vessel and the possibility of a German listening station on the coast of Greenland. The Coast Guard boarded and seized the SS Buskø, a Norwegian vessel operating under German instructions. They then landed a party and seized a radio and codebook from the outpost, and took the prisoners and ship back to Boston. The ship and men were later released.
Amid the naval conflict, the Coast Guard had already assumed responsibility for port security, overseeing movement of ships and safety of harbors, shipyards, and industrial facilities. This set the stage for the Coast Guard's transfer to the Department of the Navy, placing them directly under control of the Chief of Naval Operations, who had already been involved in organizing the Greenland Patrol. The Coast Guard had been previously transferred to DotN in World War I, so the naval leadership was cognizant of the extra ships and manpower the Coast Guard could offer the Navy.
Once transferred, the Coast Guard not only used its own ships but also manned over 500 Navy and Army vessels, from landing ships to transports to auxiliaries, to destroyer-escorts. I've selected a few stories to highlight the performance of the Coast Guard in World War II.
The Coast Guard manned the USS Big Horn (AO 45), a merchant ship fitted with hidden guns (also known as a Q-ship). She sailed the Atlantic in both convoys and by herself, waiting for U-boats to attack before revealing her weaponry. She fought off a couple submarines, although did not have any confirmed kills.
USCGC Campbell (WPG 32) escorted a convoy that was attacked by a wolf pack of at least 12 U-boats. Campbell depth-charged six U-boats, then dropped back from the rest of the convoy to assist a sinking tanker, and rescued 50 merchant mariners from it. On her way back to the convoy, she followed radar and sonar contacts, finding a surfaced U-boat. Too close for her guns to fire, Campbell instead rammed the U-boat and then depth-charged at point-blank.
Campbell took five prisoners as the crew of the U-boat abandoned ship. The collision also ruptured the hull of Campbell, flooding the engine room. Fearing losing the ship, all prisoners, rescued mariners, and non-essential crew were transferred to other ships in the convoy. The remaining crew controlled the flooding, but Campbell lost power and sat dead in the water for four days before receiving a tow back to Newfoundland.
Signalman First Class Douglas Munro commanded a group of 24 landing craft and evacuated a battalion of Marines from Point Cruz, Guadacanal. Using several craft, including his own, as a shield for the evacuating Marines, he was mortally wounded. He received the Medal of Honor for his actions, the service's only recipient. The commander of the battalion of Marines Munro evacuated was Lt. Colonel Lewis "Chesty" Puller, the most decorated Marine in history.
Sources:
https://www.navcen.uscg.gov/pdf/iip/history/The_Coast_Guard_and_the_Greenland_Patrol.pdf
http://www.ibiblio.org/pha/7-2-188/188-29.html
https://www.usni.org/magazines/navalhistory/2016-10/coast-guards-world-war-ii-crucible
http://coastguard.dodlive.mil/2018/02/tlbl-uss-big-horn-the-coast-guards-q-ship/
http://www.uboatarchive.net/U-606A/U-606INT.htm
https://www.usni.org/magazines/proceedings/2018-09/coast-guards-medal-honor-recipient
http://coastguard.dodlive.mil/2018/02/tlbl-uss-big-horn-the-coast-guards-q-ship/