There are a number of ways The Basin use to communicate with each other in Guild Wars.

Communication Methods

In-game Chat

The most obvious way of communicating. One may use the guild chat to speak with the specific subguild you are a member of. Unfortunately, due to a guild member cap of 100, not all Basin members are in the same guild as you. To solve this problem, we have relayers that can take a request to relay a message and forward this one to the other guilds. Our relayers are members of more than one guild; thereby allowing them to do this. If you are a member of a party to do a quest, mission, or to participate in a competitive game, you are advised to instead use the team chat in any messages that are supposed to go to your party and not to the entire subguild.

Additional information about how to use the in-game chat