Raven II was 394inchesft5inchesin (ftin) long, had a beam of 51feet, and a draught of 27inchesft6inchesin (ftin).[1] She was rated at 4,706 GRT. The ship had one propeller shaft powered by one quadruple-expansion steam engine that used steam generated by an unknown number of coal-fired boilers. Raven II had a maximum speed of 10kn.[2]
The German freighter SS Rabenfels was built by Swan Hunter & Wigham Richardson and completed in December 1903. On the outbreak of war in August 1914, she was seized by the British authorities whilst in Port Said, Egypt and was requisitioned for service under the Red Ensign in January 1915 to operate seaplanes.[1] No special modifications were made to the ship; the aircraft were stowed on the aft hatch covers and handled with her cargo booms.[3] Aenne Rickmers operated two French Nieuport VI.H floatplanes that had been off-loaded by the ; they were flown by French pilots with British observers.[1] Later, the ship operated included British Short Type 184, Sopwith Schneider, Sopwith Baby and Short Admiralty Type 827 floatplanes.[4]
For the first two months of 1915, the ship and her aircraft supported Allied operations in Syria, Palestine and the Sinai Peninsula. Aside from reconnaissance duties, they delivered and recovered Allied spies as well as observed for ships performing coastal bombardments. Around 20 March, Rabenfels arrived in Mudros to load the aircraft and crew of the damaged Aenne Rickmers (later HMS Anne).[3] The ship was commissioned into the Royal Navy on 12 June 1915 and renamed HMS Raven II.[1] On 17 August, both Anne and Raven II spotted for the French armoured cruiser as she bombarded Tarsus.[3] In January 1916, she was assigned to the East Indies and Egypt Seaplane Squadron together with the carriers, and Anne. The squadron was under the command of the General Officer Commanding, Egypt and its primary duty was to watch Turkish positions and movements in southern Palestine and the Sinai in early 1916.[5]
At the end of March, Raven II was sent to the Red Sea to attack Turkish troops threatening Aden; she carried one two-seat Short floatplane and five Sopwith Schneiders for this operation. After a preliminary reconnaissance mission, on 2–3 April her aircraft dropped ninety-one 20lb bombs as well as leaflets urging the Arab auxiliaries to desert. The ship returned to the Syrian coast for patrols and was transferred to Kastellorizo in early July to conduct aerial reconnaissance and bombing missions in that area. Raven II was transferred to the Gulf of Aqaba later that month to take aerial photographs of the head of gulf as well as the east coast of the Red Sea. Her aircraft observed for the monitor as she bombarded a Turkish encampment in the Sinai. One aircraft was forced to land, but it was taken in tow by the monitor and delivered back to Raven II.[6] The East Indies and Egypt Squadron reassembled in late August with Raven II, Anne and Ben-my-Chree and the aircraft from the three carriers attacked the Turkish supply dump at El Afule for thirty minutes. The squadron then steamed south along the Palestinian coast where they encountered two Turkish supply dhows. One was sunk by the escorting while the other was captured. The squadron flew off seven aircraft that attacked an encampment at Bureir and a nearby railroad viaduct. Raven II was then sent to the Adalia area on the Turkish coast where her aircraft bombed a factory at Fineka and searched for U-boat bases[7] On 1 September, the ship was in Port Said preparing for another sortie into the Red Sea when she was hit by a bomb dropped by a German aircraft (probably the first successful air attack on an aviation vessel). Although Raven II was only lightly damaged, Anne was sent in her place. Raven II relieved Anne on 26 October in the Red Sea and her aircraft bombed Turkish forces advancing on Rabigh and Yenbo on 10 December. Shortly afterwards, the ship was transferred back to the Eastern Mediterranean where her aircraft attacked a bridge over the Ceyhan River with one 65lb bomb and eight 16lb bombs on 27 December.
On 10 March 1917, Raven II and the sailed for the Indian Ocean to hunt for the German Q-ship Wolf. For this mission she carried a Short Baby and two Short 184s. The two ships searched the Laccadive Islands en route to Colombo, Ceylon, which they reached on 2 April. They then searched the Chagos Archipelago and the Maldive Islands and returned to Colombo. Engine problems forced a Short 184 to make an emergency landing on 21 April in the Maldives; the crew rejoined the ship on 6 May after a series of adventures that inspired Rudyard Kipling's story "A Flight of Fact".[8] Raven II recovered the floatplane and its aircraft continued to fly search missions from Colombo until 21 May. She then joined a convoy bound for Egypt and arrived back in Port Said on 10 June. In early November, the ship's aircraft observed fire for a variety of ships during the Third Battle of Gaza.[8]
HMS Raven II was paid off shortly afterwards and, renamed Ravenrock, served as a collier under the Red Ensign from January 1918 until the end of the war under the management of Grahams & Co. She was sold to British Dominion Steamship Co. in 1923 and resold later that year to Karafuto Kisen Kabushiki Kaisha (KKK), which renamed her Heiyei Maru No. 7. In 1935, the ship was sold to Inuri KKK and she was renamed Heiei Maru No. 7 in 1938. The ship was sunk during the Second World War, although the circumstances are unknown.[9]