Note: Not my idea, just posting for those that don't know. Works best on Xbox only servers. Working on basis of max 3 ships, for easiest results.
Now, for this to work, you need 6,8,9 or 12 crew (inc yourself). These numbers are divisible by 3 (Brig) and 4 (Galleon), for 2 or 3 ships at your disposal.
Everyone loads in a Brig or Galleon (closed crew), and puts up a reapers mark, plus tells everyone their co-ords. Everyone looks at map. If 2 or 3 ships find each other (depending on what you need), everyone else joins them.
Now just alliance up, and you can all sail together. I hope this was helpful, and I wish you the best of luck in your travels.
