tsarevitch

Thanks for letting us know!

Nicholas II [Russian: Николай II, Николай Александрович Романов, Nikolai II, Nikolai Alexandrovich Romanov (18 May 1868 – 17 July 1918)] the last Tsar of the Russian Empire with his only son Alexei Nikolaevich Romanov (Russian: Алексе́й Никола́евич) (12 August 1904 – 17 July 1918).

If this picture was from March, 1917, this was probably taken at what was the Russian Army's headquarters in Mogilev, in present-day Belarus, where the Tsar spent long periods as commander-in-chief. He went there on March 7, 1917, during violent riots in St. Petersburg. He was forced to abdicate the throne on March 15, 1917.
en.wikipedia.org/wiki/February_Revolution#Tsar.27s_return...

en.wikipedia.org/wiki/Nicholas_II
ru.wikipedia.org/wiki/%D0%9D%D0%B8%D0%BA%D0%BE%D0%BB%D0%B...
en.wikipedia.org/wiki/Alexei_Nikolaevich,_Tsarevich_of_Ru...

Czarewitch (on the negative here, written Czarewitsch) is an older variant transliteration of Царе́вич, now more commonly written in English as Tsarevitch, meaning any male son of the Tsar.

And see:

Alexei Romanov, only son of Tsar Nicholas II of Russia and Tsaritsa Alexandra.

See notes under

Beautiful

A nice 'close in' shot, very interesting picture of the old ship, thank you for sharing.

The Tsesarevich (Цесаревич) was a battleship of the Imperial Russian Navy, built in France by Compagnie des Forges et Chantiers de la Méditerranée à la Seine. en.wikipedia.org/wiki/Russian_battleship_Tsesarevich