The answer is that you travel to Hawaii by airplane, and then you can rent a car after you arrive.
If you're traveling from Vietnam, there are currently no direct flights to Hawaii. You'll need to take at least one connecting flight, usually through cities such as Tokyo, Seoul, Taipei, Manila, Los Angeles, San Francisco, or Seattle. Depending on your route and layover time, the total travel time is typically between 16 and 25 hours.
Another option is to visit Hawaii by cruise ship, although this is much less common. Most cruises depart from the west coast of the United States, such as Los Angeles, San Diego, Seattle, or Vancouver, and usually take between 7 and 18 days.
Since Hawaii is the 50th state of the United States, international visitors generally need:
A valid passport.
A valid U.S. tourist visa (B1/B2), unless they are eligible for the Visa Waiver Program.
The best times to visit Hawaii are April to June and September to November, when the weather is pleasant and there are usually fewer tourists. The period from December to March is also popular because it's whale-watching season and offers excellent surfing conditions, although prices tend to be higher.
Many people are surprised to see tourists driving cars around Hawaii. The reason is simple: they fly to Hawaii first, then rent a car after they arrive.
Most visitors pick up their rental car directly from the airport. While Oahu has a relatively good public transportation system, renting a car gives travelers much more flexibility to explore beaches, scenic lookouts, hiking trails, and local towns at their own pace.
On islands such as Maui, the Big Island, and Kauai, a rental car is almost essential because many attractions are spread far apart and are difficult to reach by bus. One of the best examples is the famous Road to Hana on Maui, one of the world's most scenic drives.
In short, the typical trip to Hawaii looks like this:
Fly from your home country to Hawaii.
Pick up a rental car at the airport.
Drive around the island to explore beaches, volcanoes, waterfalls, and other attractions.
Return the car before your flight home.
So, while you often see tourists driving in Hawaii, they don't drive to Hawaiiâthey fly there first and then rent a car to explore the islands.