[Little Ray]

During WWI, the Ottoman Empire’s fleet was mostly obsolete (pre-dreadnaught) and not very seaworthy.

The most effective units were a couple of German ships, the SMS Goeben and SMS Breslau. Both were transferred to the Ottoman Empire Navy, the Goeben became the Yavuz Sultan Selim, and the Breslau became the Midilli. The Germans donned Turkish uniforms and fezzes and continued to crew them.

The Ottoman Empire DID have some very brave and clever fellows working the minelayers in the Bosporus and they actually bagged some battleships by clever mine placement...

[Vigilanteman]

If I remember my World War I history right, both the Goeben and Breslau were trapped in the Mediterranean when the war broke out.

With Great Britain in firm control of the Straight of Gibraltar, there was no way they were going to get home. So the next best thing was to arrange a flag transfer to the Ottoman Empire in the manner you described.

While you are right about most of the Ottoman's fleet being out of date, the sheer numbers were impressive enough to:

1. Block the Bosporus as you describe.
   
2. Keep the Russian fleet from operating in the Black Sea.
   
3. Contribute to the disastrous British defeat in the Gallipoli Campaign, 1915-1916.

Winston Churchill, First Lord of the Admiralty, suffered a near fatal career setback for his role in the campaign whereas an obscure Ottoman commander named Mustafa Kemal managed to parlay his outstanding performance into being Ataturk, the first leader of modern Turkey.