This was a good post from last year regarding Cinco de Mayo. Believe me, I checked, since we're arriving that day and wanted to dive in the afternoon. If that wasn't possible, we were going to find a fiesta grande and trade the nitrogen bubbles for the Superior bubbles.
http://www.scubaboard.com/showthread.php?t=88275
http://www.scubaboard.com/showthread.php?t=88275