What happens to the Italian, French and Russian navies? If Germany gets control over them, then India like the rest of the British Empire becomes German
At most the Russian will hand over is 7 Battleships however OTL 2 did not survive the war and one entered service late in the war as its machinary was British and delayed for some reason (delayed indefinitely if the British thought she was going to become a German ship) - so the Germans depending on when events happen likely get 4 at most and some of these the Ganguts were never in great shape - not helped by being run aground on several occasions.
And its likely that the Russian Revolution will occur before any handover can happen so making any agreed handover unlikely
France has what - 4 Courbets and then the 3 Bretagne class ships - which entered service early 1916 - so possibly not finished if France is defeated early
None of these 14 ships comes close to a British Dreadnought of that period and even with all 14 the German fleet is still weaker than the Royal Navy.
So how does some or all of these ships being handed over make the British Empire become German?
Any German Victory has to be early before 2nd Ypres ideally earlier than that - perhaps the sickle cut works in 1914 - whatever.
I suspect that any such victory would be even early in the war likely 1914 and the results would look similar to 1870 - with the British being virtually unimpacted by the results outside of losses suffered by the initial BEF as the war ends before Kitchener's army and those of the Commonwealth can be fully raised and deployed.
No as Peg Leg Pom says - Britain Cuts its losses as it would have no choice as France would have thrown in the towel and I suspect that relations are pretty much normalised very quickly and any captured German Colonies handed back.
Very unlikely that the rest of the world takes much notice of another European spat.