Edwyn Gray, Devil Flotilla, 1978
United Kingdom
HMS Rapier
S Class Submarine
Details as per the real ships.
HMS Unwieldy
U Class Submarine
Details as per the real ships.
France
Gladiateur
Submarine, class not specified
No other details provided.
Poland
ORP Bielik (Erne)
Orzeł Class Submarine
Details as per the real ships.
Note: 'Erne' is the name of bird of prey known as the Sea Eagle. The Orzeł Class was named after birds of prey, making this the only class of submarine it can be. This would make it the third member of the class after the ORP Orzeł (Eagle) & ORP Sęp (Vulture).
Netherlands
HNLMS Zwaardvisch (As spelt by author 'Swaardvis')
Submarine, class not specified, but most likely O Class.
No other details provided.
Note: Thanks to Arjen for the suggested corrections. As they point out in their post below the O Class were the class of submarines the Dutch used in European waters, the K Class was used overseas. Both classes used numbers rather than names.
Norway
Unnamed
Two 'Coastal' Submarines
No other details provided.
Germany
Heinrich Ullmann
Type 1934 (or 1934a) Class Destroyer
Note: Stated to be the only German Destroyer to survive the First/Second Battles of Narvik. Details provided are sufficient to narrow it down to either the Type 1934 or Type 1934a Class but no closer than that.
Friedrich Ihn (Z-14)
Type 1934A Class Destroyer
Real ship, details as in service.
Note: Author simply gives the pennant number when referring to this ship.
Z-19
Destroyer, class not specified
Note: Pennant number is that of the Type 1936 Class Destroyer Hermann Kunne sunk at the Second Battle of Narvik.
Z-27
Type 1936A Class Destroyer
Real ship, details as in service.
Note: This destroyer was not comissioned until 1941, in the novel it is in service by May 1940.
Plot summary: The year is 1940, as the Germans launch their assault on Western Europe, a special multi-national flotilla is assembled to carry the fight to the enemy, but as the Western Allies fall, how long will the force be able to keep up the struggle.
Note (Spoiler): This is the second of a four book series that begins with 'Fighting Submarine' (1978), like the U-Boat series that started with 'No Surrender' (1974) the series follows a single officer through WWII, in this case British.
The time frame of the novel is from 9 May 1940 to 14 July 1940.