Fairy optic motorcycle

Please help with our propsed trip to Vietnam? - scuba market

My husband and I want to go to Vietnam and Cambodia, possibly (we were in Thailand). We are in our late 20s, not really into parties / clubbing or something.
We love eating in restaurants, beautiful scenery, snorkeling, diving, cultural experiences, markets, animals, things.
Can someone me a place that interests us, with these activities in mind?
Thank you very much :-)