Trading with other players is essential in every trade sim, and it will be even more personal in this game.
Proximity and voice chat will help you define the need of items you want to exchange with the other player, or maybe you need ale for the crew and want to change it for some nice map information or sightings?
You will also be able to team up to stand stronger against the challenge ahead regarding pirates or english authority.
I think you need a bit more information for this post to feel like the time to click was worth it.
Maybe if the image was a video, this small amount of text would do.