I have been going to Ha Long Bay for the last five years. Food is consistent. Service not so much. It's a very busy place at lunch hour and over the weekend. Be prepared to wait for a table, particularly on Friday and Saturday nights. Not uncommon if you wait over an hour.
Servers will get it on the table don't expect pleasantries or being made to feel like your business matters. Food is ok better than average. Not amazing.
Today is was there for lunch. Unfortunately I got the least interested server they have. With restaurant clear after lunch rush I waited for 20 minutes to have my order taken. It comes with soup. As I watched my server count money. He brought soup 15 minutes later. Lunch came out shortly thereafter. He got my order wrong. I ate it having only 10 minutes before I had to go back to work. He brought my bill before I was finished. I placed the money on the table. Now he moved quickly for the first time. He made change at the table and stood nearby waiting for a tip. I left 10% reluctantly. I had barely walked away when he immediately returned to the table to get my tip. I spoke to the owner as male server came over to listen to my concern. No understanding. Owner told me to ask for another server the next time I come in.
This male server has been horrible on past visits as well. No apologies given. I was late getting back to work.
Assuming I'll be back to ask for another server was a stretch. Service will leave a bad taste in your mouth