Nandaihe is accessible by beidaihe (around 20m for 30-40RMB). We spent a day at the beach, we went over to ‘fairy conch island’ via the cable car. I would recommend getting there early as soon as it opens to start queuing as we were stood for around 2hours. On the island there is multiple rides which only cost 20-30rmb a go, bungee jumping for 180rmb, scuba diving etc. You could spend an entire day there and not get bored. Food and drink is slightly on the pricey side over on the island (10RMB for a small bottle of water) so would recommend to bring supplies over with you especially in the hot weather.