DL and NW have filed a $96 round-trip base fare in the SAT-CZM market. $196.76 all-in for the itinerary I chose. Since the fare is exactly half of AA, CO, and US's fare, perhaps it was intended to be a one-way and was misfiled as a round-trip.

The fare class is T on DL and K on NW. Two-day minimum stay. Good through the end of schedule. Pretty decent inventory around many weekends, holiday weekends excepted.

This is a great fare for San Antonio and Central Texas-based scuba divers or those who want to take the ferry across the mainland to Playa del Carmen.