We have several events for the month of April shokko. The map changes for each event. Watch the very top set of notes in the Forum. Each Friday daddog posts a brief on ech event for the coming week.
The Coral Sea map is going to be up most of the times on the weekends because that event will be running on Saturday afternoons, and the teams will be practicing at previously scheduled times.
Also, you never know what your going to have in terms of arena settings unless you coordinate with a CM that can prepare the arena for you.