Just this week I had to go to San Jose and could not drive my car so instead I rode with a friend to San Jose and then left myself without a ride back to Playas del Coco. After the failed attempts to convince my uncle and anyone else to take a trip to Guanacaste from the crowded streets of San Jose, I decided to manage my own transportation on the public bus system.
If you don't know much about the bus systems here in Costa Rica like me then you need to do a little research and hopefully this will help you in the future.
Playas del Coco has its main bus company that services to Liberia and San Jose called Pulmitan de Liberia. The main office in San Jose can be found by almost any cab driver as most of the bus stations are within 1 mile of each other and many on the same block. In Coco, the main location is on the main road about 1 km from the beach and can be found on the map here.
First things first. Where do you get a ticket? It is usually best to purchase your ticket ahead of time especially if it is over a busy Costa Rican holiday. If you do not have this luxury than get there early to secure your seat. I was lucky and happened to be near the bus station the day before so the purchase was quick, easy and CHEAP. It cost c4,095 (or about USD $8.20) to go all the way to Playas del Coco!
There are various times to depart from Both San Jose to Playas del Coco or vice-versa. I choose the 8am departure which actually left at about 8:05am. The bus was a nice double decker that seated about 85 people and was not very crowded on my trip.
Although this says that it is from SJ to PdC, there are about 10-12 stops in between that really don't take very long except for a 20 minute break where you can use the restroom and grab something at the convenient store located there and is about halfway through the trip. Keep in mind: No restrooms on the bus. So I was VERY HAPPY that we stopped there after having a coffee and big bottle of water!
All in all, Pulmitan was a very clean bus and made a rapid trip and arrived at 1:35pm, totaling 5 1/2 hours. Which is not too bad considering the seats were comfortable and it was only $8.20.
Now if you are going to/from Tamarindo and San Jose this would be another bus company called Alfaro. I have not taken them yet but did see there buses and they seem like nice buses as well.