Japanese losses Earnings_and_losses were light : 29 aircraft and five midget submarines lost Earnings_and_losses , and 64 servicemen killed Killing .

The purpose Aiming of `` Wigwam '' was to determine Deciding the vulnerability of submarines to deeply detonated Attack nuclear weapons , and to evaluate the feasibility of using such weapons in a combat situation .

The Atlantic U-boat campaign Military_operation of World War Military_operation I ( sometimes called the `` First Battle Hostile_encounter of the Atlantic '' , in reference to the World War II campaign of that name ) was the prolonged naval conflict Hostile_encounter between German submarines and the Allied navies in Atlantic waters—the seas around the British Isles , the North Sea and the coast of France .

To counter Attack the German submarines , the Allies moved Motion shipping into convoys guarded Defending by destroyers , blockades Besieging such as the Dover Barrage and minefields were laid , and aircraft patrols Patrolling monitored Scrutiny the U-boat bases .

`` Lusitania '' fell Motion_directional victim to torpedo attack relatively early in the First World War , before tactics for evading Escaping submarines were properly implemented Action or understood .

In late May and early June 1942 , during World War II , submarines belonging to the Imperial Japanese Navy made a series of attacks Attack on the cities of Sydney and Newcastle in New South Wales , Australia .

On the night of 31 May – 1 June , three `` Ko-hyoteki '' -class midget submarines , each with a two-member crew , entered Arriving Sydney Harbour , avoided Preventing_or_letting the partially constructed Sydney Harbour anti-submarine boom net Earnings_and_losses , and attempted to sink Motion_directional Allied warships .

Two of the midget submarines were detected Know and attacked Attack before they could successfully engage any Allied vessels , and the crews scuttled Destroying their submarines and killed Killing themselves .

Two of the midget submarines were detected Know and attacked Attack before they could successfully engage any Allied vessels , and the crews scuttled Destroying their submarines and killed Killing themselves .

These submarines were later recovered Recovering by the Allies .

Immediately following the raid Military_operation , the five Japanese fleet submarines that carried Carry_goods the midget submarines to Australia embarked Process_start on a campaign Military_operation to disrupt Hindering merchant shipping in eastern Australian waters .

Immediately following the raid Military_operation , the five Japanese fleet submarines that carried Carry_goods the midget submarines to Australia embarked Process_start on a campaign Military_operation to disrupt Hindering merchant shipping in eastern Australian waters .

over the next month , the submarines attacked Attack at least seven merchant vessels , sinking Motion_directional three ships and killing Killing 50 sailors .

During this period , between midnight and 02:30 on 8 June , two of the submarines bombarded Attack the ports of Sydney and Newcastle .

the allies had learned Education_teaching of the completion force 's composition and goals through intelligence gained Getting from decrypting japanese radio signals , and plans were developed Coming_to_be for coordinated attacks Attack on it by submarines and united states army air forces ( usaaf ) aircraft .

As part of these preparations , 26 submarines were eventually positioned Placing along the ships ' expected route .

However , attempts by it and several United States Navy submarines to attack Attack between 11 and 14 February were unsuccessful .

Despite this success , the Japanese Government was forced Motion to discontinue Process_end its efforts to ship oil from Southeast Asia to Japan in March due to the heavy losses Allied submarines were inflicting Bodily_harm on oil tankers , and all the ships of the Completion Force were sunk Motion_directional in or near Japanese home waters before the end Process_end of the war .

A group of German submarines attempted to intercept Preventing_or_letting the carrier force as it returned Arriving to base , without success .

The Germans were joined Becoming_a_member by submarines of the Italian Royal Navy ( `` Regia Marina '' ) after their Axis ally Italy entered Arriving the war Hostile_encounter on June 10 , 1940 .

The outcome of the battle Hostile_encounter was a strategic victory Earnings_and_losses for the Allies—the German blockade failed—but at great cost Cost : 3,500 merchant ships and 175 warships were sunk Earnings_and_losses in the Atlantic for the loss Earnings_and_losses of 783 U-boats ( the majority being Type VII submarines ) and 47 German surface warships , including 4 battleships ( `` Scharnhorst '' , `` Bismarck '' , `` Gneisenau '' , and `` Tirpitz '' ) , 9 cruisers , 7 raiders , and 27 destroyers .