1. Why?
- From the Sea of Marmara, they threaten not just the Anglo-French in the Mediterranean, but also the Russians in the Black Sea (whom they now massively outnumber)
- With the Black Sea coast now vulnerable to potential Ottoman landings, Russia would have to pull men away from the fronts that matter
- It would be much harder for the Anglo-French to blockade the Aegean the same way they did the Adriatic
2. When?
- Shortly after the Ottoman Empire joins the war and before the Otranto Barrage is set up. (the PoD is that such a contingency is planned for before the war)
3. Drawbacks?
- Maintenance would eventually become an issue, but then everyone was expecting a short war anyway, and most pre-war estimates emphasized that a long war would be disadvantageous to the Central Powers, so it's kind of a moot point anyway
- Italy might feel emboldened to declare war...however, they did so OTL anyway soon after it became clear a fast German victory was not in the cards
- There's a certain risk that the ships might be lost whilst transferring, affecting overall morale
4. What ships?
- Head to Constantinople:
4
Dreadnoughts
9
Pre-dreadnoughts
3
Armoured cruisers
2
Torpedo cruisers
2
Protected cruisers
2
Scout cruisers
15
Destroyers
25 High Seas
Torpedo craft
- Stay in Adriatic:
3
Coastal defence ships
3
Protected cruisers
2
Destroyers
29 Coastal Torpedo craft
6
Submarines
5. Effects?
...