As the number-one tourist attraction in northeastern Vietnam , Halong Bay draws a steady stream of visitors all the year-round. From February to April the weather in this region is often cool and drizzly. The ensuing fog can make visibility low, but this adds an ethereal air to the place and the temperature rarely falls below 10°C. During the summer months tropical storms are frequent, and tourist boats may have to alter their itineraries, depending on the weather. It is hard to do it any cheaper on your own, but some travelers prefer to steer their own course. Traveling independently allows you to take more or less time in places, depending on the weather. The downside is that it is hard to arrange an overnight on a boat this way.   Most of the others have long favored shuttle bus or private transfers to Halong Bay which normally take about 3 hours per way, cost a few more bucks but way more convenient and comfortable.