I took a package for our Underground River Tour so I don’t have to go through the hassle of falling in line to get our permits. The agency where you got your package tour will handle this for you. I’m not sure how much it costs for a DIY but it is offered at Php1300 – 1500 when I search online. I got a package for both Underground River Tour (includes all permits, entrance fees, van transfers, boat transfers, and a buffet lunch) and Firefly Watching (which we did not avail anymore) for Php2000 per head. The underground River Tour package costs Php1500. I got the package tour from Kuya Jun which I got from PEx.
We were picked up by Kuya Jun at our hotel at 10am. We had to travel going to the wharf for 1 – 1 1/2 hours. We had our lunch at Sabang. The buffet lunch was nothing special but they served their specialty, I guess. They’re mostly seafood and I’m not much of a fan of seafood that I’m not familiar with. 
After lunch, we walked to a port nearby and waited for our turn to ride a small boat that will bring us to the Underground River.
After a short boat ride, we arrived at the Underground River. The place was tranquil with fine sand and huge rock formation. There were also monkeys roaming around freely. We were informed beforehand by our guide NOT to bring plastic bags or bottled water as the monkeys tend to snatch these from you. We walked at the registration area and waited for our turn to go through the Underground River while taking several pictures.
The tour was just 45 minutes. It was a very informative and entertaining tour. The boatman tells you everything you need to know about the Underground River as well as the rock formations found inside.The boatmen obviously have a script for the tour which includes the jokes that they to tell. They speak English to accommodate the several number of foreigners that flock one of the Seven Wonders of Nature.
It’s definitely a must-see. I felt that our trip to Puerto Princesa is pretty much accomplished after having gone through the river tour. The rest of the activities are just bonus. 🙂
When we were on our way back to the hotel, we decided not to go through the Firefly Watching since the bridge that we must pass thru going there is under construction. We had more free time to settle down and freshen ourselves up since we were not able to check in at once in the hotel.
Other Puerto Princesa Posts:
agitopassim 
Good day! I would just like to ask how we can also avail of the Php2000/pax (Underground River Tour and Firefly Watching). We are a group of 10 going to Puerto Princesa on July. Thanks a lot.
Hi Reych! You may contact Kuya Jun at 09175414366. For your reference:https://agitopassim.wordpress.com/2012/09/02/puerto-princesa-expenses-and-contact-persons/
Thanks for the reply. This is such a big help to us.
No prob! Happy to be of help. Enjoy your vacation! ^_^