The main battery of the island defences was Battery No 43 placed at Cape Zerel. This battery was constructed under extremely difficult conditions. The 12 inch gun barrels weighed 50.7 tonnes each and everything had to be brought to Zerel by barge. In addition to the mountings, power plants, barracks and magazines had to be constructed. When first test fired in April 1917, the four 12 inch guns had the portentous range of 152 cable lengths (one cable equalling 200 yards or approximately 183 metres) and not only covered the entire Irben Straits, but also the shore of the Kurland coast. However, advantage of this reach could not always be taken because of frequent fog and mist, especially in autumn, when visibility did not exceed 90 to 100 cables. Nevertheless, this extremely important battery had a couple of drawbacks. The installations were in the open, without protection, and the magazines were constructed of timber and earthworks with oak doors. This would later have tragic consequences.
There were two other batteries on the Zerel Peninsula. Battery No 40, of four 120mm cannons, was built near Karust and Battery No 41, of four 130mm guns, was positioned between Mento and Lebera. Most of the aforementioned batteries were well protected by numerous 75mm anti-aircraft gun batteries.
The second part of the defences of the Irben Straits were the extensive minefields laid over a long period. Since the beginning of the war the Russians alone had laid over 10,000 mines in the Irben Straits, and the Germans had laid thousands more along the Kurland coast as part of their so-called ‘mine shield’. However, from the Russian point of view, there were no guarantees the mine position could be supported. The southern coastline of Kurland lay in German hands and they were thus able to conduct minesweeping operations close under the coast, without the support of their fleet units. These minesweepers, however, frequently came under attack from Russian destroyers and gunboats operating in a swept area under the Sworbe Peninsula, the so-called ‘manoeuvre basin’, and also from the newly-commissioned Zerel battery. The struggle between laying and sweeping mines continued over 1915, 1916 and 1917 and was referred to as the ‘static war’, or a maritime version of trench warfare. The southern Moon Sound was protected by two large minefields of around 1300 mines.
The third part of the Russian defence were the naval units, which were known as the Naval Forces of the Riga Gulf, or MSRZ. This force was considerable and consisted of the following:
Commander: Vice Admiral Bakhirev.
Chief of Staff: Captain 2nd Rank Muromtsev.
Flagship: Bayan
Battleships: Slava, Graschdanin
Cruisers: Admiral Makarov, Diana
Gunboats: Chrabry, Grozyashchi, Chivinetz
Destroyers
Commander: Rear Admiral Stark.
Flagship: Novik.
I Division Torpedoboat-Destroyers
II Division Torpedoboat-Destroyers
III Division Torpedoboat-Destroyers
IV Division Torpedoboat-Destroyers
V Division Torpedoboat-Destroyers
VI Division Torpedoboat-Destroyers
Submarines
C26, C27, C32.
Fleet train
Guard Ship Division of the Baltic
VIII Torpedoboat Division
XI Torpedoboat Division
Minelayers: Pripyat, Amur, Wolga
Five Divisions of Minesweepers.
The air stations at Lebara, Kielkond and Arensburg could field around fifty seaplanes and flying boats and ten land-based Nieuport types. The Russian forces were well balanced and their ships had all had combat experience and had proved themselves tough adversaries.
The main base for the Naval Forces of the Riga Gulf was Kuiwast Roadstead, which was convenient and safe, as was the destroyer and submarine base at Rogekul, but they were removed from the Irben Straits. There were auxiliary bases at Arensburg and Piya Bay for the light forces but they were not secure against U-boats. The Moon Sound channel was the main arterial link for reinforcements but even with its dredged depth it was considered impassable for the battleships Andrei Pervozvannyi and Respublika (formerly Imperator Pavel I).
The leader of the Naval Forces of the Riga Gulf was Vice Admiral Michael Koronatovich Bakhirev, known to his colleagues as ‘Crown’. Rear Admiral K. K. Pilkin wrote of him: ‘He was a clever, simple and kind person. He was trusted, listened to the opinions of those older, more experienced in naval traditions, and was very popular in the Fleet’. Vice Admiral Bakhirev was born on 17 June 1868. He served with distinction in the Russo-Japanese War and was much decorated. He began the First World War as commander of Rurik, the fleet flagship. In December 1914 he was promoted Rear Admiral and was given command of the 1st Cruiser Brigade. He led this unit in the Battle of Ostergarn on 2 July 1915. In December 1915 he was appointed commander of the 1st Battleship Brigade, the dreadnought squadron. He survived the murderous ravages of the revolution and was already a Vice Admiral and Commander of the Mine Defences of the Baltic when in summer 1917 the Commander of the Fleet, Vice Admiral Verderski requested him to familiarize himself with the state of affairs in the Riga Gulf. On 2 August the new Fleet commander, Rear Admiral Razvozov, gave him the following order: ‘In the case of the beginning of an operation by the German fleet in the Riga Gulf, I charge you, honorable Vice Admiral, to take up the overall command of the Naval Forces of the Riga Gulf and Moon Sound Position and to conduct actions as previously discussed’. Vice Admiral Bakhirev was frequently in the Gulf after that and collected the staffs aboard the transport Libau, on Kuiwast Roadstead, which was connected to shore by telephone. M. K. Bakhirev was later murdered by a Bolshevik court on 9 January 1920, after refusing to flee to Finland.
The morale of the Russian crews and garrison was also an imponderable circumstance. During the revolution many officers had been murdered or replaced and new commanders were sometimes elected by the crews. Each ship had an elected committee with which the officers had to consult. In 1919 Vice Admiral Bakhirev wrote a report about the actions of the Naval Forces of the Riga Gulf and he described the situation thus: