The idea is to get people to feel more like they are on a team when the dialog windows pop. So in addition to the normal dialog window with an NPC, show portraits of the other captains in a video conference call style. Under each portrait is a dialog box with the most recent thing they have said. Upper corner to the side is a normal chat box showing the chat history of the team.
I have a mockup jpeg however I am getting an invalid file error trying to upload. Happy to email if requested.