A 1-day tour to Halong Bay can be a worthwhile experience if you have limited time and want to get a glimpse of the stunning scenery and iconic karst formations. It allows you to visit some of the highlights and provides a good impression of the beauty of the bay. However, it’s important to keep in mind that the journey from Hanoi to the harbor can take around 2.5 hours each way, which means a significant portion of the day will be spent on transportation. If you’re seeking a more immersive and relaxed experience, consider opting for a longer cruise duration.