Napoleon therefore came early to the conclusion that he must bring about a concentration of his seagoing fleet in the Channel, which would give him a temporary command of its waters.
More important work was done by the seagoing boat U21, Lt.- Comm.
This was by now active, four other seagoing boats having followed U21 from the North Sea, and it is claimed that 50,000 tons of shipping were sunk in the Mediterranean and Aegean during Sept.
At the end of that month the Germans had nearly one-third of their total available submarine force in this theatre-14 boats out of 44 - of which 5 seagoing, 2 small and I mine-laying boats, were working in the open, and 3 small (UB7, 8, 14) and 2 mine-laying (UC13, 15) at Constantinople.
Sulina is the only free port on the Danube, and is much used for the transhipment into seagoing vessels of grain which is brought down the river in large lighters from Rumania, Russia, Bulgaria, Servia and AustriaHungary.