The Bio Bay Moon Phase Calendar has been updated for 2009, so if you are planning on checking out one of the three Bio Bays here in Puerto Rico, make sure you arrange the dates to correspond to the best nights to go.
As a quick summary, the following dates will NOT be good for visiting the bio bays (you should contact one of the bio bay tour operators to confirm the dates when they will not operate):
September 1-4 and 29-30
October1-4 and 28-31
November 1-2 and 28-30
December 1-2 and 28-31
Note: Reputable Bio Bay tour operates will not operate a tour on nights when the moon phase is bad for seeing the bio bays.
You can find the full Bio Bay Moon Calendar here.