A friend of mine recently started a kickstarter for a first person age of sail ship combat game called blackwake. They have managed to get up to 100+ players in their tests and they want to get up to 300 Players per match at the most. Things such as Cannonballs, Grapeshot, Chain-shot, and the like are planned. As well as full destructible ships that you can board and sink. They also have plans for a PvE Sea monster mode. Which multiple ships team up against a Kraken like sea monster. They are using Unity3D Free and have come very far. If you can please pledge your support for blackwake. I personally want to play this. Here is a video as well - You can find the Kickstarter - >> here << Please note that I am not affiliated with its development team. I just want to play this!
So... Star Citizen circa 1680? Sounds pretty cool actually. NESSIE!! Also, since you said your friend started the Kickstarter, I'm pretty sure that counts as an affiliation. Just saying.
Star Citizen of the open seas pretty much. I am not sure if they have plans for a persistent world so to speak. But I do want the Flying Dutchman.