Yes. Players can play in groups of up to three. Skull and Bones is also fully cross-platform and cross-progression, so playing with friends is possible regardless of the platform you are on.
Here’s a quick recap:
You can team up with two other players for a crew of three.
Skull and Bones boasts cross-play, so you can pillage with friends even if they’re on a different platform (PC, Xbox, or Playstation).
Your progress carries over too, thanks to cross-progression.