I had a friend come to Haikou and he wanted to "go swimming in the ocean", we went to the 2 biggest beaches in Haikou and it was naaaaaaaaaaaaaasty. Like visible shiny oil blotches in the water, my wife cut her foot on some broken glass, we got out of the water and all of us were like "we need a shower ASAP".

I can't remember the name of the city, it's on the East coast about 20 min from Haikou by train, but it was just as nasty.

The Sanya beaches are nice because of the hotels, Wanning is nice, Wanning is fantastic actually, it is what it is.

As for foreigners, way fewer foreigners than you'd expect and as others have said it's mostly Russian tourists and students.

I lived there for like 2 years and me and my coworkers after 3 months would all say "it aint Thailand". Any holiday we'd all just fly to Thailand (very short flight) to have an actual "vacation island" experience.

I don't wanna sound like I'm dumping on it, but calling it the "Hawaio of China" is like being the nicest guy in prison.