Let's play with some map effects to get this looking a bit more like the island map we've got for the setting.
The first thing we need to do is take a duplicate of the basic threshold layer (where everything darker than a certain shade is blackened, and everything above that shade is whitened). Then we manually go through it with the "magic wand" tool selecting everything that's black...the seas, the inland lakes, everything. Then delete it.
Duplicate this, and basically treat it like a mask layer. The topmost layer will blank out everything beneath it, the layer just under it has a "bevel and emboss" blending effect applied to it. I like t think it looks a bit like the edges of continental plates sinking away to the ocean floor.
If we fade the beveled layer a bit, to pull the "sea-floor texture" back into the image, but keep that uppermost layer opaque, it looks more like a chart that might be used by a nautically inclined culture of people.
Next, just beneath that uppermost opaque layer we draw some vertical and horizontal lines, along with a couple of radial compass lines (off the top of my head, I can't remember what these are called on charts, I just know that I used them on the island map.) Then maybe throw in the skull and cog compass rose that was created for the island.
I like where this is heading. Time to start naming some things with vaguely exotic titles.
The Empire of the Sun is toward the right on this map, it needed to be somewhere close to, but detached from, a great desert (where the church's ancient prophet did his wandering and preaching). Since, the Empire exists in a vague analogue of late-renaissance/early-industrial Europe, I also tried to make sure it appeared in the part of the map that has the most "European looking" landmass. This is purely an aesthetic judgement call. A few more lands are named around it, to give justification for the variant languages that have been described in our setting.
As we get further away from this "hub of civilization", the names of lands get more widespread. This is a map from their perspective and far off lands aren't as well identified. Some areas might be rich in heritage, but lived in by nomads or scattered groups, thus they'd be identified as deserts, wastelands, or even just left unnamed. Maps drawn up but other cultures might cluster their named and identified areas around other parts of the chart.
But where is our island of adventure in it's archipelago of mystery?
I can think of a few good contenders.
The first is the ocean just north of "the Dragon Kingdoms" just to the right of the leftmost set of compass lines. There are a couple of islands in the middle of the ocean that would be difficult to get to, and they are far enough away from the Empire of the Sun that they could have been completely unknown until recently.
Next, just a bit further east, heading toward the Kingdom of Byakush there is a convoluted landmass, currently unnamed.
Otherwise, at the furthest west on this map, and in the northern hemisphere (just west of the land we've designated "Tankay"), there are a few scattered large islands.
I'll think of the right spot for our adventures overnight. No point rushing into these things.