| What you see | Karst islands close to the mainland piers; caves with walkways (Sung Sot Cave), the climb on Ti Top Island, Luon Cave by bamboo boat or kayak. | The islands and lagoons off Cat Ba Island; listings name kayak and swim stops, cycling in Viet Hai village and Cai Beo floating village. | The islands northeast of Halong Bay toward Van Don, such as Quan Lan and Minh Chau, with fewer boats. |
| Who runs it | Quang Ninh province. The fee is collected by the Ha Long Bay - Yen Tu World Heritage Management Board. | Hai Phong city. Fees are collected by the Cat Ba Bays Management Board, under the Cat Hai special zone. | Quang Ninh province. Decision 43/2024 names the Bai Tu Long National Park Management Board as its bay management board. |
| Official routes | VHL1 to VHL8 on the board's list; route 2 is Ti Top Island and Sung Sot Cave. | No fixed route list: routes are those announced by the competent authority under current rules, so ask which stops your cruise makes. | 10 routes, BTL1 to BTL10, plus three connecting routes from Halong Bay. |
| Nights on board | Overnight fees are set for routes 2, 3 and 4. Boats must be inside the overnight anchorage by 19:00 in summer, 18:30 in winter. | Anchorages are those the authority announces; none is fixed in the rules, so ask where your boat spends the night. | The Mang Ha overnight anchorage (Điểm neo đậu nghỉ đêm Máng Hà) on routes BTL5 and BTL6; Lao Dong reported an anchorage opening at Hang Nha Tro in May 2026. |
| Bay fee, day visit | VND 250,000 per visit per person on route 1 or 2 (Quang Ninh Provincial People's Council, Resolution 51/2025) | VND 120,000 per adult per visit (Hai Phong City People's Council, Resolution 47/2025) | Collected by the Ha Long Bay - Yen Tu World Heritage Management Board; ask whether your listing includes it. |
| Bay fee, one night on board | VND 550,000 per visit per person on route 2, VND 500,000 per visit per person on route 3 | VND 400,000 / 300,000 per person (adult / child), instead of the day fee | No per-route fee published; ask the seller whether an entrance fee is in the price. |
| Where you board | Tuan Chau International Marina or Ha Long International Cruise Port at Bai Chay. | Ben Beo or Gia Luan pier on Cat Ba Island; or the Halong piers on a crossing cruise. | Ao Tien port in Van Don, Cam Pha port, or the Halong piers on a connecting route. |
| From Hanoi | By road on the expressway: 105.5 km to Hai Phong, then 25 km to Ha Long. The listed shuttles state 2.5 to 3 hours. | Bus, then speedboat or ferry to Cat Ba Island. Viator's Cat Ba Express listing states 3 hours 15 minutes to 3 hours 30 minutes (approx.), as the operator gives it. | The same expressway past Ha Long; the Quang Ninh expressway runs on through Van Don, 176 km in all. |
| Crossing between bays | Since 20 April 2026, routes VHL3 to VHL6 may continue into Lan Ha Bay, overnight only. | Reached from the Halong side on those connecting overnight itineraries. | Three connecting routes follow Halong route 4, then sail on into Bai Tu Long Bay. |
| Kayaks and bamboo boats | Only between 5:30 and 18:30 local time. Whether kayaking runs on your date: check with your operator. | Only between 5:30 and 18:30 local time. Whether kayaking runs on your date: check with your operator. | The Halong rule applies to both bays. Check with your operator. |
| Boat hours | Summer 5:00 to 20:00 local time, winter 5:30 to 19:00 local time. | Hai Phong sets its own summer and winter hours. | The same hours as Halong Bay, under the same decision. |
| Who stops boats in a storm | The Quang Ninh Inland Waterway Port Authority stops departure permits. | No departure in a dangerous weather warning. When the port authority, traffic police, border guard or the Cat Ba Bays Management Board order boats back, the captain must comply. | The same Quang Ninh port authority as for Halong Bay. |