Halong Bay has the postcard. Phu Quoc has the privacy. If you have one yacht trip in Vietnam, here's the honest comparison.
Crowds: Halong has hundreds of boats; Phu Quoc has dozens. On a Phu Quoc charter, you'll see another yacht maybe twice all day.
Water clarity: Phu Quoc wins — by a lot. Halong is beautiful from above, but you don't swim there. Phu Quoc you swim, snorkel, and dive.
Weather windows: Halong is November to April. Phu Quoc is year-round, but November-April is also the best.
Pricing: Comparable. Both deliver luxury at fair prices.
Halong is a one-time wonder. Phu Quoc is a place you return to.
