HMS E14
commanded by Edward Boyle¹
managed
to enter
the sea
of Marmara
and to fire
torpedoes
against four vessels
of the Ottoman Navy ²
which did not imagine
that a submarine
would reach there
passing
athrough the Straits
avoiding
the mines
so accepting
finally that
no matter what the
propaganda
of the Ottoman Turkish Empire declared
the Straits
were not impregnable.

1.Then Lieutenant Commander, later Rear Admiral Edward Courtney Boyle VC (23 March 1883 – 16 December 1967)
2.27 April 1915, the second Allied submarine to penetrate the Straits. Boyle received the Victoria Cross, the highest award for gallantry in the face of the enemy that can be awarded to British and Commonwealth forces.