Vietnam is low land, facing the Pacific oceans which will compress and force water under great pressure to move toward the Indian Ocean. Thus, there is a doubling effect of the water that will assault the coasts, in that was sloshing inland into Vietnam during the flood tides that occurs during the shift and the hours following will not be a passive flow, but a scouring flow. As with Thailand, none remaining in Vietnam are expected to live. Boats and hapless humans dragged along with a scouring tide will find themselves dragged under, unable to resist the flow, until long past the drowning point. After the shift, Vietnam will quickly go under water in any case, being low land, as the existing poles melt and the oceans rise some 675 feet above the current sea level. Like the Philippines, Vietnam will not be a country after the shift.
Note Indonesia Elevation Loss commentary.
Note Southeast Asia commentary.