Did I get my currents and wind directions right?

[Caenwyr]

Hi all! I'm currently writing a section for my novel where one of my protagonists will be travelling by sailing ship (story is set in a world roughly equal to our 18th century). They are sailing from the city of Gaendyr (marked A on the very crude map below) to the port of Tash-Gawri (B) across the Silver Sea. And it looks like a lot of fun to use this voyage to tell something about the world without actually launching into a 20 page monologue that will bore everyone to death. I rather have the readers experience something than force them to read a dry piece of text.

But: I want my voyage to be plausible, wind direction and current-wise. So I have two questions:

1. are the currents and winds I worked out in this map correct? I'm mostly interested in the region inside the green box so please ignore any but the most blatant mistakes outside of that. Is it safe to assume that there will be a clockwise gyre in that almost closed-off but massive body of water?
2. How would a merchant travel from A to B taking into account the prevalent wind and ocean currents?

Here's the crude map as promised:


If you're looking for some eye bleach to recover from that horrid mess, please take a peak at my topographic map for the same region, that looks a tad more pleasing to the eye.