The Balkan Wars
IOTL the Hellenic Navy's control of the Aegean Sea seems to have played an important part in the war because it restricted the number of troops the Ottomans could send to reinforce their army in Turkey in Europe.
At the outbreak of the Balkan Wars the Hellenic Navy consisted of:
- The armoured cruiser Averof. She was laid down at the Italian Orlando yard in 1907 and purchased by the Greek Government in October 1909, launched in March 1910 and completed in May 1911. She displaced 9,958 tons. Her armament was four 9.2", eight 7.5", sixteen 3" and two 47mm guns, three 18" torpedo tubes. Her maximum speed of 22.5 knots;
- 3 Hydra class coast defence ships displacing about 5,000 tons and armed with five 150 mm guns;
- 4 Nici class destroyers. They were ordered from A.G. Vulkan in 1905 and completed in 1906-07. They displaced 350 tons, had an armament of two 12pdr and four 6pdr guns and two 18" torpedo tubes. Their maximum speed was 30 knots;
- 4 Thyella class destroyers. They were ordered from Yarrow in 1905 and completed in 1906-07. They displaced 380 tons, had an armament of two 76mm and two 57mm guns and two 18 torpedo tubes. Their maximum speed was 32 knots;
- 2 French Labeuf type submarines ordered in 1909 and completed in 1912.
The Greeks also bought 2 destroyers building for the German Navy at Vulkan in July 1912 and 4 destroyers building for Argentina at Cammell Laird on 12th October 1912 just as they were about to sail for Argentina. The protected cruiser Helle wasn't bought by Greece until 1914 having been originally ordered by China from the New York Shipbuilding Co in 1910 and completed in November 1913.
Meanwhile the most effective units of the Ottoman Navy IOTL were:
- The 2 German pre-dreadnoughts purchased in 1910. They displaced 9,900 tons, had an armament of six 280mm eight 105mm and eight 88mm guns. Their maximum speed of 16.9 knots;
- 2 protected cruisers completed in 1904. Although build to different designs displacing 3,330 and 3,830 tons respectively they had the same armament of two 6", eight 4.7", six 3pdr and one 1pdr guns and two 18" torpedo tubes. They also had the same maximum speed, 22 knots;
- 4 French Durandal class destroyers ordered in 1906 and completed 1907-08 which displaced 284 tons. Their armament was one 65mm and six 47mm guns and two 17.7" torpedo tubes. Their maximum speed was 28 knots;
- 4 German S 165 class destroyers purchased in 1910 which displaced 665 tons. Their armament was two 88 mm guns and three 17.7" torpedo tubes. Their maximum speed was 33 knots.
However, the most effective units of the Ottoman Navy ITTL were:
- 2 St Vincent class battleships ordered in 1908 and completed in 1911. These were instead of the German pre-dreadnoughts purchased in 1910. They displaced 19,560 tons. Their armament was ten 12" and twenty 4" guns and three 18" torpedo tubes. In addition to having a considerably superior armament to the German ships of OTL their maximum speed was 21 knots, not much slower than the Averof;
- The TTL cruiser Drama laid down in 1907 at a British yard and completed in 1910. She would be a Boadicea class scout cruiser. Her displacement would be 3,300 tons. Her armament would have been six 4" and four 3pdr guns and two 18" torpedo tubes. Her maximum speed would have been 25 knots;
- The two protected cruisers completed in 1904;
- The 4 Durandal class destroyers;
- The 4 destroyers ordered in 1908 instead of the German destroyers purchased in 1910. They were probably oil burning versions of the British Beagle class. Their displacement was 945 tons. They were armed with one 4" and three 12pdr guns and two 21" torpedoes. Although their gun armament was heavier than the German destroyers purchased in the real world they were slower at 27 knots. But the British Beagles were coal burners, the Turkish ships would be oil burners and that might give them a few knots extra speed. All the other ships in the Ottoman Navy would be oil burners ITTL too and that might make them one or two knots faster as well;
- 2 British D class submarines ordered in 1908 and completed in 1911. These ships were armed with three 18" torpedo tubes.
IOTL the Greek reacted to the German ordering of 2 dreadnoughts in June 1911 by ordering the Salamis in July 1912. She was not laid down until July 1913, presumably because the design was changed in December 1912 and her projected completion date was March 1915.
I'm not sure that the Greeks could have afforded to buy one or two dreadnoughts to counter the Turks 1908 TTL order for 2 St Vincent class dreadnoughts. Even if they could and still ordered their ships from Germany the projected completion date would have been September 1912. That is on the basis of the 2 Turkish ships being ordered in December 1908 for delivery by the end of 1911, which was 2½ years ahead of the June 1911 for Turkey's first 2 dreadnoughts.
In the TTL situation I think the Greeks might have been better off buying some submarines with the money they used to buy Averof with IOTL.