Answer :
The answer is they sailed in convoys protected by battleships. Real examination of delivery misfortunes in World War I discredited every one of these contentions, in any event so far as they connected to transoceanic and other long-separate activity. Boats cruising in guards were far less inclined to be sunk, notwithstanding when not furnished with an escort. The loss of profitability because of guard delays was little contrasted and the loss of efficiency because of boats being sunk. Ports could bargain all the more effortlessly with caravans since they had a tendency to land on timetable thus stacking and emptying could be arranged.