Hah! Red Seas Under Red Skies was going to be my suggestion as well.
For nautical adventure, I have four recommendations:
The True Confessions of Charlotte Doyle: this is a children's book (roughly 6th-grade level) that's spectacularly good. 19th century (I think) shipping vessel with a tyrannical gentleman captain.
Treasure Island: I mean, come on now. But if you've never read it, it's 100% worth the time. Long John Silver is among the greatest villains ever written. If you ever wanted to see what chaotic evil looks like with one leg and 20 charisma, read this.
Master and Commander: just excellent high-seas adventure.
His Majesty's Dragon and sequels: 18th-century naval adventure, with dragons and politics. There's no real magic except for dragons, but they're plenty.
For coastal stuff, I have a weird one: David Copperfield. Certainly not all the book applies, but there are some truly excellent bits set along coastal England, from a poor family that lives in an upturned ship turned into a house, to a thrilling scene of a shipwreck just offshore, you could do a lot worse.
Check out a double CD set called Rogue's Gallery. I think they even did a volume 2. I'll try to find a link in a bit.
Edit: Link to the set on Amazon https://www.amazon.com/Rogues-Gallery-Pirate-Ballads-Chanteys/dp/B000GGSMD0
There are a bunch on Twitch, but I kinda liked this one:
I signed up for his patreon and used them A LOT so far. They went off the rails with Skerrin and are slowly getting brought back into the story line but it was super clutch on the smugglers boat and the salvage quest. My players really enjoyed actually seeing the pieces in a similar way. They were looking at the different weapons and stuff. I even printed out some of his "fluff" pieces like cocoons. I'm going to use this alot in the Isle of the Abbey quest. Gonna make that certain part of it a real dark place.
I went and bought heavy paper at wal mart. I can't remember the weight but it felt similar to a birthday card, maybe a little thinner.
I bought these from Amazon. The pdf from the minis lets you click and change how they print out. I did it so they were mirror images so when you fold them it shows the front and back of the character. Print, cut them out, fold over, stick in the holders. Works great. I can't remember exactly how I did it but you can also set up the mini how you want and then copy the image over to a Microsoft Word doc and I would create a whole sheet of various mini's for all the encounters. Just lock the aspect ratio of the image and set width to 1". Print one big page and cut them all out. I had them paper clipped together for each encounter. Then put them in their holders and deploy them onto the battle mat.
I will say that my laser printer did not like paper so for my next encounter I'm probably going to cut the card stock into blank 1"x 2" pieces and print the minis on normal printer paper. Maybe glue them to the blanks. I had a few feeding issues and the toner on a few didn't adhere very well near the end of the page.
I have the regional map for the entire area, and I believe there was a section on Keoland. I'll check after work and post any screenshots I can. The map is from 3E, but it's all information you can use regardless of game edition.
Greyhawk Gazetteer for anyone interested.
I bought the same set. I've used them for lizardfolk and dragonborne. Excellent sculpts and details. I used the large creature for a BBEG encounter.