A fan favorite fic of mine is Plunder. It's an E rated DabiHawks Omegaverse Pirate Fic. It's a longfic with just over 100k. Chapter length is around 3-4k. Currently working on a sequel called Plunder:To Catch a Rose.
Summary
Touya has wanted to be a sailor for as long as he could remember, a dream his father nurtured...until he presented as an omega. Shortly after a pirate attack Touya is dropped at an omega school and left there for years. When his brother arrives to liberate him, Touya assumes it's so he can finally return to the Endeavor, and be the sailor he always knew he was. Instead, he's told he's been promised in marriage to a Keigo Takami--a landowner and merchant. And probably old as the hills and a landlubber, to boot.
Alpha Keigo Takami has a second identity--the well known and feared pirate Hawks, captain of the Ghost (if you see her, you're about to become one). He decides to get a look at the man his uncle Tsunagu promised was his perfect match, and raids the Endeavor. When Touya raises a sword, determined to fight him, Hawks falls hard and fast, already dreaming of their honeymoon. Which is how he ends up bargaining with Touya for a kiss...and then more.
Link https://archiveofourown.org/works/39096528/chapters/97804290