In the first six verses, there's assonance in all the ending rhymes, with the /iː/ sound. This makes the rhymes super elegant and fluid and helps to subtly bind those lines together - you've got the perfect rhymes (sea/me, sweep/weep/ and bleed/greed), and then their shared vowel sound. I find that a great bonus for the way the poem reads 
The typography and line breaks feel nice and natural everywhere, too, not forced at all. I will say that I'm a fan of the lineation here: ""Dearest.../ My black sea,/ forgive these children -"". It's written out in a really intuitive way that is great for anyone who may recite this piece. I can totally imagine the cadence and intonation to use for a narration of this. Not to mention, I just like how you leave suspense after "dearest" - it's a really good word to follow up with a caesura.
I like your imagery, nice and sensory without being over-the-top. You've got a good balance between words like "ruefully", "doleful", "wistful", and plenty of simple but effective words: sea, ripples, ravens, children. The repetition of "sea" is pretty logical, given the title, and it's just a good word to bring back a few times - you're keeping the theme present the whole time. Though chaotic, stream-of-consciousness poems can be FANTASTIC, I am a pretty big sucker for works that stick more or less to one theme (or at least define a theme and return to it eventually). Yours does that super well! You're using the semantic field of the sea the whole time: winds, tides, sea, ripples, sands, waters... etc etc. The reader stays by the imagined shore the whole time, and imo it's lovely 🩷
I don't have much constructive criticism for you except maybe the very beginning. "A repose, I shall, by this black sea" just doesn't make much grammatical sense. I'd recommend using repose as a verb so that you just have Repose, I shall, by this black sea.