I was on a Commadore cruise (before they went under , so to speak) . Progresso was one of the stops. On board the ship they pretty much said there was nothing to do unless you booked a tour. I was watching my pennies & did not want to go on a tour but decided to get off the ship to see what I could find. It is a very long pier & they have trolly like things to take passengers to the dock side areas. There is not a lot at the port, but when you get off & walk into town just a short ways there is a very beautiful beach. They had chairs & umbrellas on the sand so I walked down in that direction. A local boy came up to me & rented me a chair with umbrella for the whole day (or as long as I stayed) for 3.00. What a deal. The water was so beautiful & the beach was so clean that I was a little suspicious of it. I wondered why the shore person on the ship did not mention it in her talks. I guess that they wanted to sell shore excursions. When I finished on the beach I walked up into town just a short ways & stopped at a very nice open air restaurant and had a very reasonable priced & good Mexican lunch. This was a very laid back stop, but I enjoyed it the most of any on the cruise.
This port was very new & unspoiled at the time. It will probably not stay that way.
Hope this helps
PS I found a couple of pictures of beach & pier in Progresso. I will post the one of the pier after I post this one of beach.