To enable the fps limiter, right-click the Show Overclocking button and select Driver Profile Settings.. From here, find the Frame Rate Limiter listing under the Common subheading and choose an fps limit from the dropdown box. You may need to play around with the limit depending on the games being played and your monitor's refresh rate if you experience any screen tearing or other visual oddities.
Details. Though there is no cost to get into El Yunque National Forest (for hiking, etc.), there is a small entrance fee for El Portal Rain Forest Center. They charge $4/adult and $2/senior. Kids under 16 are free. They collect the entrance fee upon entry to the parking lot. Your National Park Service passes are valid here.
The only ferry runs from Playa del Carmen, which is about an hour's drive south of Cancun. The two passenger ferries, run by Cruceros Maritimos and Ultramar, cost approximately 163 pesos each way per adult and 97 pesos per child and takes 25-45 minutes each way to cross, depending on water conditions and passenger load.