The Battle of Britain Five Months That Changed History, May—October 1940 by James Holland (z-lib.org).epub

Shipping had met Ramsay at Dover on the 20th to discuss the many thorny
problems involved in such an operation. The first was that the sleek
destroyers and minesweepers that made up most of the navy’s ships were
filled with guns and depth charges and not designed to carry large numbers
of men. That meant using merchant ships, fishing vessels, cross-Channel
ferries and pleasure boats to carry out most of the work. Small boats would
also be called upon, particularly to lift men from the gradually sloping
beaches. Ramsay, for one, knew only too well from his experiences in the
last war that the shoal-ridden coast off Dunkirk was rarely more than two
fathoms deep and a notorious graveyard of ships.
The problems facing them on 20 May had multiplied by the morning of
27 May, when Captain Bill Tennant reported to Admiral Ramsay, some
thirteen hours after Operation DYNAMO – as the evacuation had been
called – had officially begun. Until 6 p.m. the previous evening, Bill had
been Chief Staff Officer to the First Sea Lord at the Admiralty, but as
something of a navigation expert – not least as Navigator on HMS Renown
on the Royal world tour of 1921 and as a naval instructor at the Imperial
Defence College before the war – Bill had been plucked from that job and
sent instead to report to Admiral Ramsay in Dover. From there he was to be
sent to Dunkirk to organize the shore end of the evacuation as Senior Naval
Officer (SNO) there, where his navigation knowledge would prove
invaluable. Lean-faced, with dark determined features, the 49-year-old had
immediately packed a few things and by 8.25 p.m. had set out first for
Chatham and then gone on to Dover.
It was not until 9 a.m., however, that he finally reached Ramsay’s
headquarters, a warren of rooms carved into the high chalk cliffs at Dover at
the beginning of the last century by French prisoners of war, and at a time
when Britain had last faced the threat of invasion. Ramsay’s own office had
a window and a small iron balcony overlooking the Channel; a cannon here
had once pointed towards France, but now it was guns across the sea that
could be clearly heard. Further inside the cliffs was a large chamber that in
the last war had housed an electrical power generator, and so it was called
the ‘Dynamo Room’. Now, it was the nerve centre of the evacuation plans –
hence Operation DYNAMO. It was here, at Ramsay’s HQ, that Bill was
briefed by the Vice-Admiral. When DYNAMO had been first conceived,
Ramsay had expected to be able to use a number of Channel ports. Now, it
seemed, they could barely use one. The port at Dunkirk had already been so