Pool hopping is very easy. If staying at HRH or PBH, you can easily walk to the other. To go to RPR, you can take the water taxi. If staying at RPR, it's easy to take the water taxi to Citywalk then hop on the water taxi to PBH or HRH. The hotels aren't right next door to each other, but it's no problem taking the boat or walking. We have always stayed at RPR and visited both PBH's beach pool and the HRH pool. Just show your room key at any pool and pick up the towels you need.