Hm, I’m not a diver, but the food is uh-ma-zing. I’ve forgotten how it’s spelled, but there’s a crazy little omelette-like veggies & shrimp dish that’s called (pronounced like) “bun siao” (siao rhymes with meow). NOM-tastic. Street-vendor food was various and really good. Seriously, there’s a reason Anthony Bourdain’s done several shows on Vietnam. Ho Chi Minh City (locasl still call it Saigon) is really great. My time there was too short though. Lovely, street culture was fascinating and there seem to be a lot of spontaneous things going on. Set aside time to wander your district, wherever you’re staying.
Good luck and I don’t need to wish you have fun, I know you will.

To dive? No, but to see, a lot of things.

War Museum
CuChi tunnels
Central Market, many things to buy and very cheap

If you can, make a trip to Cambodia by boat. Is amazing

Cheers

Con Dao Island is wonderful for diving i hear.
My most definitive reconmendation for diving and holiday would be Phu Quoc though :) it’s simply a fantastic place to be. As is Saigon.
and the “bun siao” thing is Banh Xeo, meaning fried cake = Pancake :) it’s dough is usually made of a mix of rice, bean and wheat flower and quite different from western pancake, and of course not sweet.

All of your answers are awesome!

Are you just in HCMC or going to explore the rest of Vietnam? You could knock off HCMC in a couple days. I liked Hanoi better and Halong Bay is definitely a place not to miss. Siem Reap was amazing but not a ton to do in Phnom Penh although it sort of sucks you in. I did enjoy my stay there. The bus ride from Siem Reap to PP is worth it, too. You see how people live and the countryside. Definitely fly if you’re going to Hanoi. If you’re leaving Vietnam, check out your visa to make sure you get multiple entries- it costs more.