If possible I'd like to render this using a case-ending rather than prepositions. Can the locative express this meaning fully? I'm wondering whether ëaressë is taking too much poetic licence, or whether that would be read as 'at sea' or 'on the sea'?
It would indeed place the hope into or on top of the sea. 'Across the sea' means 'beyond the sea' or 'on the other side of the sea' and Tolkien actually gives this construction in Quenya a lot of thought in PE17:65. He arrives at the prepositions lá
and haila = palla
with sample phrases caitas lá/palla i sír
'it is (far) beyond the river' (static position) and lendes lann'/pallan(na) i sír
'he came (to a point) (far) beyond the river' (motion). I'm not sure whether this was intended to replace pella
'beyond' in Namárie (of course you could use that too).
And one final question. First I have to invoke a Párendili golden rule that no question is too simple, because I suspect this one will be on the borderline. To express a phrase such as 'they see us', is it allowable to use two long pronominal endings in the same word, i.e. cénantelmë [céna + -ntë + -lmë] ? It doesn't create any forbidden clusters, but I'm unsure of it and haven't yet come across an example of this kind.
In 'they see us' one pronoun is nominative and the other one accusative. We see that short suffixes are used for accusative pronouns, as in utúvie-nye-s
. But it seems that there are no short pronouns in the 1st person plural, they are always some kind of modification of me
(excl.) or we
(incl.). I think it might be possible to use me, we
as accusative suffixed pronouns, *cénanteme, *cénanteve
(one might compare álamë tulya
'don't lead us'), but I would rather prefer a separate pronoun - *mé/vé cénante