I just called the hotel, and they told me that they have a $350 Pesos (about 32 USD) day use fee (kids 50% off) this allows you to use the pool, lounge charis, etc.(meals are not included) The place is awesome and well worth the visit, but, it's way to expensive for my taste. A cab will charge you about $35 USd each way. Here's there email so you can contact them directly:
aca.subgerentes@fairmont.com
I recommend the Hyatt for a day at the pool, much closer and they allow cruise visitors to use their facilities, only have drinks or lunch. It' nice and clean.
The ocean in Acapulco is usually quite rough and dirty,at the Princess the swell is only good for surfing, not much for swimming and a strong under tow current.
At the Hyatt it's much calmer and much, much cheaper. A cab will charge about $12 USD each way