This act immediately starts off with news of the Turkish fleet sinking. Why? What’s the point of having this in the plot at all? Aside of course from having Othello arriving.
I’m leaning toward the answer being ‘foreshadowing.’
“The wind-shaked surge, with high and monstrous mane,
Seems to cast water on the burning Bear
And quench the guards of th’ ever-fixed pole.” lines 13-16.
The ‘guards’ referred to are two bright stars in the Ursa Minor constellation. I think it’s reasonable to say these stars could represent Othello and Desdemona, and the storm represents Iago’s vileness and manipulation, to say it nicely.
See, the storm represents Iago because it’s full of ships, and he’s full of shit–
It also lets Shakespeare get rid of no longer plot-relevant points in the play though that’s almost bad writing, at that point, in my opinion.
Anyways, I feel like this is a definite foreshadowing of the coming tragedy, and it makes me wonder: when this play was first performed, would the audience be aware ahead of time that it’s a tragedy? Or would this foreshadowing be all the more effective for them?