This section is from the book "The Wonder Book Of Knowledge", by Henry Chase. Also available from Amazon: Wonder Book of Knowledge.
The great mission of the submarine during the European war was as a commerce destroyer. Many ships were sunk and many lives, with cargoes of great value, were lost, and it was not until the summer of 1916 that the submarine appeared in a new role, that of a commerce carrier. On July 9th of that year the people of Baltimore were astounded by the appearance in their port of a submarine vessel of unusual size and novel errand. Instead of being a destroyer of merchandise, this new craft was an unarmed carrier of merchandise. It had crossed the Atlantic on a voyage of 4,000 miles in extent, laden with dyestuffs to supply the needs of American weavers.
This new type of vessel, the "Deutschland," was an undersea craft of 315 feet length and a gross tonnage of 701 tons, its cargo capacity being more than 1,000 tons. It had crossed the ocean in defiance of the wide cordon of enemy warships which swarmed over part of its route, and reached port in safety after a memorable voyage, to the surprise and interest of the world. Leaving the port of Bremenhaven on June 18th, and halting at Heligoland for four days to train its crew, it made its way across the Atlantic in sixteen days. During this voyage it lay for two hours on the ocean bottom in the English Channel and was submerged in all not over ninety hours, the remainder of the voyage being made on the surface.
Its crew, composed of twenty-six men and three officers, found their novel voyage rather agreeable than otherwise. Supplied with plenty of good food, a well-selected library, a graphophone with an abundance of music records, and other means of convenience and enjoyment, their voyage was more of a holiday then a hardship, and they reached their transatlantic port none the worse for their hazardous trip. It was not the longest that had been made. Other submarines had voyaged from German ports to the eastern limit of the Mediterranean, but it was the most notable and attracted the widest attention.
The return voyage promised to be more perilous then the outgoing one. A fleet of British and French ships gathered around the outlet of Chesapeake Bay, alert to capture the daring mariners and their ship, if possible. Ready to leave
The German Merchant Submarine "Deutschland" which Crossed the Atlantic in 1916, after Eluding the British Blockade.
Courtesy of Baltimore American and C. & P. Telephone Co.
Baltimore on July 20th, with a return cargo of gold, nickel and rubber, the captain of the "Deutschland" shrewdly awaited a favorable opportunity and on August 1st began his voyage, plunging under sea as he left the American coast-line and easily evading the line of floating foemen. The return to its home port a success, a second round-trip voyage was made and completed on December 11th, in the course of which a convoying tug-boat was rammed and sunk with the loss of several lives, shortly after leaving New London, Conn. The "Deutschland" was sent out by private parties, for purely commercial purposes, not as a military enterprise.
Such is the story of a pioneer enterprise, that of the use of submarine vessels as commerce carriers. It is one not likely to be supplemented in times of peace, since surface boats would be cheaper and more available. But in future wars - if such there are to be - it may point to a future of advantageous trade.
 
Continue to: