British vessels have made long voyages, and French submarines have travelled unescorted to Indo-China and the South Atlantic without difficulty or breakdown. Certain Italian boats can proceed to Italian Somaliland round the Cape of Good Hope—10,000 miles—without refuelling. Some Japanese craft of 1,400 tons are credited with seagoing endurances of no less than 16,000 miles, which means they can cross the Pacific and return without refuelling.
"While the offensive power of individual submarines has not greatly increased since 1918 their general range of action has large been enhanced. This means that submarine activity and mine-laying may be expected in distant areas formerly considered immune.
Text read from the printed page and cleaned; old type leaves the occasional error.