The mangrove boat tour was great. The tour was offered morning or afternoon. When we went the weather tended to be better in the morning with the rains in the afternoon. It is about a 90+ minute bus (nice full size bus with bathroom) ride to the mangrove. At the mangrove they have a nice pavilion with real restrooms. You then board a covered boat for a two hour ride. They point out and describe all the wildlife (crockodiles, macaw, egrets...). You can go to the bow of the boat to take better pictures if you want. At the end of the boat ride they have fresh fruit snacks, soda, water & beer and a small shopping tent for local gift items (trinkets & beads). With the morning tour you get back to the pier with several hours to walk around town.
The mangrove boat tour is the second half of the train & boat tour (which quickly sold out). The train is diesel powered (not a cool steam engine). Our tablemates took this tour and hated the train ride which had uncomfortable hard wooden seats and they were the last excursion to board the boat (we sailed the minute they stepped onboard).
We bought coffee in Guatemala and Columbia and I wish we had picked up some in Costa Rica. Columbian was $5 for a half kilo bag in the tourist areas though some charged as high as $7 or $8 so shop around. Guatemala had a greater range of coffees available and was more expensive $7 to $10 per 500g in the tourist shops and come in nice colorfull cloth bags (great for gifts).