What it says on the tin.
Includes mods for better boats, primarily Boatload, Small Ships, and Eureka! Ships of Valkyrien Skies. Those 3 mods become increasingly less vanilla in that order, with Eureka offering the ability to transform creations into physics entities.
Several mods aimed to improve ocean generation and sea life, including Aquaculture 2, Upgrade Aquatic, Biomes O' Plenty, and Ocean's Delight.
As this is a pirate mod, I of course included a few explicitly pirate themed ones, including Pirate Guns to add flintlock pistols and Lets Forge Pirates to add tons of pirate-themed armor to the game.
Lastly, this pack includes a few miscellaneous mods intended to add some interest, optimization, or QoL. Sky Structures, for instance, were included to flesh out the sky with some little islands. Mouse Tweaks is included for easier inventory management, and I've included a rotten flesh to leather mod to balance the increased use of leather with Eureka. These mods should all offer relatively small tweaks that I think compliment the other mods well, even if they aren't expressly pirate themed.
DISCLAIMER: I have played a fair amount with this pack, so I can say that it is pretty stable, but I'm not a modder, so I can't guarantee it won't crash or anything for other people.