1 sank in harbour, 1 sank on trials, 1 was sunk by gun-fire after
sinking a German destroyer off the Bight, and "C 3" blew herself up
on St George's Day against the Mole at Zeebrugge.
The losses were heavy, but were not incurred uselessly. The boats were
the outposts of the Fleet, and, however great the losses, they could
never have equalled those the bigger ships would have had to endure had
they been given the same patrols to perform.
Looking at the above list, one can see that the majority of the losses
were due to mines. Losses by direct contact with the enemy were
infrequent. This, of course, is because only a Fleet holding command of
the sea can institute regular anti-submarine methods and patrols. Our
boats were working in and around the Bight, and were taking the risks
of mine-fields all the time. The five wrecks show that navigational
difficulties are increased in war-time. This was found also by surface
vessels. The Dardanelles took their toll; it was easy to do damage to
traffic in the Marmora from a well-trained submarine, but getting in
and out of the Narrows was no simple matter. Of the two sunk by air
bombs, one was alongside in harbour, and the other was destroyed by an
Allied aircraft which mistook her for a U-boat; the submarine could
have easily dived and avoided attack, but was under the impression her
unfortunate opponent was only closing in order to make signals. The
three others sunk in error by our own side show that a submarine's
risks are great even on her own coast, and that methods of
identification can never be perfected. The enemy suffered more than we
did from errors. They had several clashes between their own destroyers:
on June 1 (the morning after Jutland) the _Stettin_ was fired on
by the whole of their 2nd Battle Squadron; while one U-boat in 1914
successfully stalked and torpedoed another (U 5), thinking it was one
of our own.