What is the correct name of the ship, Il'men or Il'mena?

Question

About 1814 the Russian-American Company renamed an old ship, called "Il'men" or "Il'mena" in works written in English. Ильмень is of course a famous lake.

Boris Dralyuk suggested to Susan Morris that obvious confusion between the spellings could be down to distinction between the nominative and genitive cases. I do have one reference to it in the Russian language, but this spelling appears to be yet a third case:

ПРОБЛЕМ А УЧАСТИЯ АНТИПАТРА БАРАНОВА В ЭКСПЕДИЦИИ НА «ИЛЬМЕНЕ» У КАЛИФОРНИЙСКИХ БЕРЕГОВ В 1814-1815 ГГ.

What is the correct name of the ship? Is the nominative case the one that should be used to refer to it in English?

Answer 1

На «Ильмене» (prepositional case IIRC) is exactly the same form for nominative "Ильмен" and "Ильмена", so I bet this is the source of confusion. It is not possible to figure out the nominative from the prepositional in this case purely grammatically.

You could surmise that a ship's name would be female, "Ильмена", although sometimes, at least in Russian, warships have male names ("врагу не сдается наш гордый Варяг"). Indeed, this article - https://ru.wikipedia.org/wiki/Илмера - says it's "Ильмена" (бриг «Ильмена»)

Answer 2

The correct name of the ship is Il'menа (Ильмена).

Ilmena was a legendary Slavic woman, after whom, as the legend holds, the lake Ilmen was named.

In English, the nominative forms should be used when borrowing Russian words, however, for other languages, your mileage may vary.

For instance, Russian, when borrowing Latin words of 3rd declension, uses genitive as the main form and drops the endings, so that Cicero becomes Цицерон < Ciceron(is), Venus is Венера < Vener(is), atlas (in architecture) is атлант < atlant(is) etc.