On June 30, 1917, the German admiralty claimed that since the beginning of the war more than 5,500,000 tons of shipping available for Great Britain's supply of food, munitions, and materials had been destroyed up to June 1, 1917, and that, on that date, there was available for this purpose from all sources only about 4,500,000 tons which, it was claimed, could be destroyed at the rate of from 800,000 to 1,000,000 tons a month.
Of the other Allied countries only France supplied from time to time definite figures. During February, March, and April, 1917, seventeen French vessels were sunk while nine others were attacked, but escaped. During May, 1917, twenty-eight French vessels were attacked. Of these eighteen escaped and ten were sunk. In June, 1917, fourteen French boats were sunk and twenty escaped. During the early part of July, 1917, two more French steamers were reported sunk having a tonnage of almost 10,000. On June 22, 1917, a debate in the French Chamber of Deputies developed the fact that the French merchant fleet was 2,500,000 tons at the beginning of the war and since that time had lost 560,000 tons, 460,000 by acts of war. During the same period 680,000 tons had been built or bought and another 140,000 was on the stocks, so that the fleet was actually greater now than before the war.
The grand total of submarine operations during February, 1917, according to figures compiled by the British admiralty, showed the following results:
Number of ships sunk—British, 110; American, 2; other belligerents, 20; neutrals, 51.
Total tonnage destroyed—British, 316,204; American, 3,322; other belligerents, 44,272; neutrals, 93,019. Grand total February 1-28, 456,817 tons.
On the other hand the German admiralty made the following official announcement on March 19, 1917; "In February 368 merchant ships of an aggregate gross tonnage of 781,500 were lost by the war measures of the Central Powers. Among them were 292 hostile ships, with an aggregate gross tonnage of 644,000 and seventy-six neutral ships of an aggregate gross tonnage of 137,500."
The State Department in Washington on April 10, 1917, gave out the following official figures regarding neutral losses inflicted by submarines:
"Information has been received by the department that since the beginning of the war, including April 3, a total of 686 vessels have been sunk by German submarines, as follows: Norwegian, 410; Swedish, 111; Dutch, 61; Greek, 50; Spanish, 33; American, 10; Peruvian, 1; Argentine, 1; total, 686. Neutral vessels attacked and escaped: Norwegian, 32; Swedish, 9; Danish, 5; Greek, 8; Spanish, 2; Argentine, 1; Brazilian, 1; American, 8; total, 66."
On May 8, 1917, a debate in the Reichstag brought out the fact that the German admiralty claimed to have sunk during February, March, and April, 1917, 1,325 vessels of all sizes and nationalities with a tonnage of 2,800,000.
Denmark on May 22, 1917, announced that since the beginning of the war 150 ships had been lost and 210 Danish seamen had perished.