Non Fishing Activities
Holbox is a sleepy little town worlds away from the likes of Cancun. So far away some people would find it too quiet! The beaches are perfecrt and are known for the shells that an be found along 30 miles of beach. The Flamingos migrate here as bird watchers can find the trip worthwhile for the variety and quantity of birds. This is not a good diving or snorkeling destination as you would be much better off in Belize or Ascension Bay ( but then you might not have the great tarpon fishery either)
You are far enough away from the main land that day trips to ruins is not a feasible idea. There is a few local craft stores in town and a few nice little restaurants. In other words unless you love fishing, beach combing, reading a book on the beach, or bird watching you may not want to choose Holbox as your vacation spot.