During your stay in Phi Phi, visit Railay in one day without having to stay overnight. With this day trip, you'll depart from Tonsai Pier at 9.30 am, travel on a shared speedboat, and arrive at Railay East Floating Pier at 10.45 am.
In Railay you can relax at one of the cozy bars, sunbathe, and if you are the adventurous type, you can try one of the experiences available. Climb giant karst limestone pillars, rent a kayak, or go for a hike to the bat cave. There are a few viewpoints looking over Railay's west and east beaches, as well as a secret lagoon where you need to climb. If you are lucky, you might also spot some monkeys on the way.
In the afternoon, take the speedboat back to Phi Phi at 3 pm and return to Tonsai Pier by 4.10 pm.