Cat Ba is an island in the Cat Ba Archipelago of Vietnam's Ha Long Bay.
Cat Ba is the largest island in the Bay and approximately half of its area is covered by a National Park, which is home to the highly endangered Cat Ba langur. This golden-headed langur is rarely seen, as fewer than 60 specimens are thought to survive in the wild, although it is the subject of a well-organized conservation program; the Cat Ba Langur Conservation Program, an international NGO that has its office at the National Park Head Quarters. The Park covers both land and marine areas and has high biodiversity, although it is at risk from too rapid an increase in tourism. Other mammals in the Park include civet cats and oriental giant squirrels.
Outside of Cat Ba town is a beautiful island with much to explore.
Please view the Halong and Ha Long Bay pages also.
The vast majority of people take a pre-booked tour from Hanoi on a tourist boat, though this is probably the slowest, least flexible and a relatively expensive way to visit Cat Ba and should be avoided at all costs unless you specifically want to be locked on a tourist boat for five hours while being given the hard sell and overcharged for the most minimal of refreshments.
It's cheaper and more flexible to come either on a non tourist boat at Halong City or via Haiphong. The Hoang Long Bus Company now leaves from another bus station, ca. 10 km south of the old quarter. The name of the bus station is Bến xe Nước ngầm (Ngọc Hồi, Hoàng Liệt, Hoàng Mai, Hà Nội). An Uber from the old quarter costs around 80,000 VND. A ticket corst 220,000-280,000 dong depending on the season (Company: Hoang Long, can be bought online/accepts international cards). Their route involves switching buses in Haiphong and is not optimal. When buying a return ticket in Cat Ba, we were offered a return ticket with Daiichi Travel, which did not involve switching buses, and included a hotel pickup and drop off. This trip is advertised on their website for 600.000, but was sold to us for 280.000 VND.
From Haiphong: there is a speed boat doing the day trip (the last one around 16:00) from Phà Binh harbour. It costs 150,000 VND (Oct 2015), but the locals pay 110,000 for the exact same ride. The price is written on the ticket but some people sell false tickets with written 180,000 and they say the price was 150,000 last year or last month! If the boat arrive in Phù Long, they can also say that 180,000 include the bus from Phù Long to Cat Ba... but it's also included in the 150,000 VND ticket: boat and bus can't be divided... it's the same company.
From Hanoi via Ha Long
- Mini Bus from Gia Lam (Hanoi) to Bai Chay (Ha Long). Tickets are bought at the ticket counter for 120,000 dong. The ride takes 4 to 5 hours with the bus stopping to pick up passengers along the way. If your bus departs Hanoi later then 10:00 am it is unlikely that you will make it to Ha Long in time to catch the last ferry to Cat Ba at 3:00pm. Note: City bus number 34 goes to Gia Lam for 5,000 dong from the following bus stops: Van Mieu, Hai Ba Trung, Nha Hat Ion, Bac Co, Chuong Duong. Be sure to wait for the bus on the side of the road where the traffic is flowing east or north. Otherwise, you may end up on a longer than intended ride around the city. Do not attempt to board bus #34 from Dien Bien Phu. The bus will run to the end of the line in the opposite direction before turning around and eventually making it to Gia Lam making what should be a short trip a two-hour ordeal.
- From Bai Chay to Ha Long City/Tourist Wharf a motorbike taxi should cost 10,000 to 20,000 dong.
- From Bai Chay to Tuan Chau Wharf a motorbike taxi should cost 20,000 to 30,000 dong.
- From Ha Long City to Tuan Chau Wharf a motorbike taxi should cost 20,000 to 30,000 dong.
- A taxi to any of these locations could be more than double.
Cat Ba/Tuan Chau Ferry takes 1 hour and costs 80,000 or 100,000 with a motorbike.
- Tuan Chau to Cat Ba 7:30 9:00 11:30 1:30 3:00
- Cat Ba to Tuan Chau 9:00 11:30 1:00 3:00 4:00
The service depends on demand. The first and last ferry of a day will always go.
Cat Ba minibus from the ferry terminal, which is on the north of the island, leaves to the main town to the south after every ferry and takes around 30 minutes costing 30,000.
Tour boats leave from the Tourist Wharf in Ha Long and take 4 hours. Route #1 as listed above the ticket counter costs 80,000. These arrive at the main town to the south.
Cat hai to cat ba by ferry(bus and people) is 40min 10h50 Friday
- Train from Long Bien (Hanoi) to Hai Phong cost is 75.000 VND hard seat and 85.000 VND soft seat (jun 2018) Trains leave Long Bien at 6:16 9:48, 3:45pm and 6:46pm (jun 2018). You can also start at Gia Lam and go to Long Biên from there. The trains leave Gia Lam at 6:15am, 9:36am, 3:45pm and 6:30pm. (September 2014.) A service from the main Hanoi station departs daily at 6:00am only.
- Ferry Pha Binh Harbour to Cat Ba by Ferry. You can buy a ticket for the hydrofoil ferry at Pha Binh/Benh Binh ferry station. This ferry brings you in 45 minutes to CatBa Town. The normal rate is 240,000 VND ($10.50) but in the low season, these tickets sell for 180,000 VND ($8).
- Bus from Hanoi to Cat Ba Island
- Cat Ba Express: Bus from Hanoi to Cat Ba or from Cat Ba to Hanoi. One trips takes to Cat Ba about 3 hours 20 minutes. Cat Ba Express’s bus schedule: From Ha Noi to Cat Ba Island pick up at: 7.30 am – 10.45 am – 14.00 pm (arrival time in Cat Ba is around 11.15 am – 14.30 pm – 17.30 pm). Normally, it takes 30 minutes to pick up tourists around Hanoi Old Quarter. From Cat Ba Island to Hanoi the time is: 9.00 am – 12.30 pm – 15.45 pm (arrival time in Hanoi is around 12.30 pm – 16.00 pm – 19.15 pm). Pick up/drop off at Hotel around Hanoi Old Quarter or in Cat Ba; The price is 14 USD/1 ticket/1 way normally. Pay on bus is possible. Sometime the Online system will have problem, you can email direct to them or contact them via their hotline.
- Good Morning Cat Ba Bus: Daily transfer from Hanoi to Cat Ba and from Cat Ba to Hanoi including Bus-Speed Boat-Bus. Pick up at hotel in Hanoi Old Quarter and drop off at Hotel in Cat Ba. There are 3 routes from Hanoi to Cat Ba inclduing 8:00am, 11:00am and 2:00pm and Cat Ba to Hanoi including 9:00am, 12:30pm and 4:00pm. Usually, time for transferring from Hanoi to Cat Ba will take from 3-3,5 hours with cost 16USD/person/one way.
- Fullmoonparty Cat Ba: Daily. Taking 4 hours by Bus + speed boat + Bus. Hanoi to Cat Ba: Departure Time /Arrival Time: 07:30 AM - 11:30 AM, 10:30 AM - 14:30 PM and 14:00 PM - 18:00 PM. Cat ba to Hanoi: Departure Time/Arrival Time: 09:00 AM - 12:30 PM, 12:30 PM - 16:00 PM and 16:00 PM - 19:30 PM Costs 250,000-280,000/person(Pay on bus). Combo bus + ticket 2way + 1 dorm bed at Fullmoonparty Hotel with 24 USD/ person. Include: Pick up/ Drop off at address /Free Wifi + Water bottle + Cold towel + Bus guide.
- Bus from Haiphong to Cat Ba: see Company Hoang Long. You can jump on their Bus from Hanoi to Cat Ba (60000VND 04/2018), the pick up is at No.04 Le Thanh Tong, Haiphong. We booked this, because we were flying into Hai phong from Hoi An, which is faster than flying to Hanoi and taking the Bus from there.
- Motorbike Taxi from Hai Phong to Pha Binh (ferry terminal)
- Motorbike Taxi from Tam Bac to Pha Binh (ferry terminal)
- Bus from Gia Lam (Hanoi) to Niem Nghia (Hai Phong) 65,000
- Motorbike Taxi from Niem Nghia to Pha Binh (ferry terminal)
- Bus from Gia Lam (Hanoi) to Cau Rao (Hai Phong) 65,000
- Motorbike Taxi from Cao Rao to Pha Binh (ferry terminal)
- Boat/Ferry from Pha Binh (Hai Phong) to Cat Ba 150,000
From SaPa to CatBa
Cat Ba Express provide Spleeping bus from SaPa go to the boat then change to a New and Comfortable Bus and drop you off at your hotel in Cat Ba.
Departure time: 20:00 (p.m), Pick up at Bus Sation and reach to Cat Ba at 7:00a.m the day after. You should be there 30 minutes before and tell to the reception that you go to Cat Ba, the staff will show you the place to wait.
Note: The current office in Sapa 38 Fansipan (Mr A Tuong), Sales Bus Sapa to Ninh Ninh, Transferred from Ninh Binh to Cat Ba by car seat very long time. From Sevice The Long Ninh Binh.
- see Cat Ba Express Bus. They pick up in Ninh Binh Center or Tam Coc then go straight to Hai Phong, go to ferry and then go to Cat Ba. It takes about 5 hours.
There are two options to travel to Cat Ba with a motorbike. Either from Halong or Hai Phong. From Hai Phong the ferry terminal is at Dinh Vu, it is located in an industrial shipping area and is not well signed, a dirt road from the main road leads to the terminal. The ferry costs 30,000 vnd to Cat Hai where you have to ride across the island and catch a second ferry costing 20,000 vnd to Cai Vieng terminal on Cat Ba island. A 26km ride across the island (through some stretches of roads in disarray) will then get you to Cat Ba town. The ferries run from 6.00am every 30 minutes.
The easier drive is from Hanoi to Halong City, primarily taking highways AH14 and QL18. The drive is prettier and covers much easier terrain. From Halong City, there are three ferries a day to the northern port of Cat Ba Island, from which it is a 40-minute drive to Cat Ba town. The ferry from Halong City to Cat Ba Island is 100,000 VND with a motorbike and 80,000 without, and is a beautiful ride through Ha Long Bay. The last ferry is usually around 3 PM (there are 2 schedules, one for low season, and one for high season, starting on april 24).
You can easily rent a motorbike from any hotel for $5 (standard) per day or less if you look around or visit in the low season.
Buy your petrol at an official petrol station (Petrolimex) so you pay the official price. A small one is located in Cat Ba Town and a bigger one on the left side when you leave the town.
The other option is to get petrol in bottles along the streets but it's much more expensive. Don't pay more than 50,000 VND for a 1.5L bottle of petrol, which can be bought in some of the small towns as well as near the port area near the end of the town.
Anyone you hire a bike from should give you a photocopied map of the island which will help you with planning.
Local buses across the island leave from the western edge of Cat Ba town, on the water near the market intersection.
There are half a dozen places to rent bikes including tandems. A ride to the other side of the island for a view into Ha Long bay and then back along the coastal road is around 45km. It's worth getting a bike with gears as there are a few hills.
- National Park, Eastern part of the island (Enter eastward on the main north/south road). The domain of the endangered Cat Ba Langur, of which there are less than 60 left. Things on offer include a walk to a peak viewing tower (1.5-2 hours round trip; slippery and muddy if it's rained recently) The tower at the top is in bad shape and climbing it is prohibited. (Viewing tower seemed restored and easily climbable on 14/12/2019.) A frog pond (probably better in the off (wet) season), a short nature walk near the frog pond, more stuff you can probably find online which is about a four hour round trip. The total distlink titleance each way is 3.63 miles and total elevation gained is about 700 feet, there are a lot of stairs made of cemented rock. 80,000VND entry, various guided tours. edit
- Caves. There are a lot of caves around the island, though none of them are particularly impressive. Some cost money and may have optional guides. You can find them using the map or signs on the island. You have to walk through some forest to some of them. edit
- Beaches, Southwest side of the island (Accessible from the road). Don't expect surfable waves, though! As of December 2019, a huge hotel resort is under construction right at this small beach. There is a lot of noise and hundreds of workers coming and going. Free. edit
- Monkey Island. Several boats run day trips to nearby monkey island either in isolation or as part of a larger tour. The island apparently has monkeys, but only a few around the accomodation were in evidence. Be aware that these animals are used to getting their food from either the guests or the bins, and therefore are not afraid of humans, so they might cause a problem. [Jan 2014] The monkeys come right up to the shore to "greet" the boats. Google "Monkey Island Bite". These monkeys bite a lot of tourists. The monkeys on Monkey Island are long-tailed macaques that were imported to the island specifically to appeal to tourists. Neither of the two native monkey species are found on Monkey Island. There is some accommodation on the island. Monkey Island Resort consists of eight small bungalows and 20 spacious deluxe bungalows, but cozy, bamboo huts just behind a secluded beach. The food was nice, the drinks cheap, and the scenery was spectacular. There's some kayaking available, and a trail for hiking to the top of the mountain where you can take so beautiful pictures of Lan Ha bay. Nearby is the public beach, destinations of lot Cat Ba island trips. It is probably the most beautiful junkyard in the region. You can see monkeys searching for food in an enormous quantity of the garbage, nobody takes care. Better to avoid to visit. approx US$40 per night. edit
- Hospital Cave, (Off Ha Sen Road, 10km from town). A 17 room underground hospital and hideout which was in use until 1975. It's a real life James Bond underground lair. Get tickets from the ticket office. There's a toilet right after the entrance. 40,000. (20.7698,107.0204) edit
- Cannon Fort, (2km north of town). )Closed in Jul 19 for maintenance. Already closed for two months, unknown when it opens again.) Built-in 1942 as a naval defense. Incredible views of Lan Ha Bay. Great place to see sunsets. (Note: if you are only interested in the views, before the ticket booth there's a path that goes all the way up to the hill on the left, first to the communications antenna, and then till the cliff's edge. Same views of Lan Ha Bay, for free. However, as it looks to the East, you don't get sunset views) 40,000. (20.7233,107.0546) edit
- Overnight cruise tours it is the newest way to explore Cat Ba Island, Hai Phong to surrounding islands and caves of Halong Bay such as Dark & Bright cave by cruise tour. In the past, if you want to visit Cat Ba island and Halong Bay in one trip, you have only one way is transferring from Cat Ba to Halong by car, but when enjoying the new itinerary- cruise tour, you will have the chance to admire the beauty of Cat Ba and Halong Bay by Era cruise of Halong-Bay-Tours. There are several services in Era cruise including Skyline Bar, Starry Mini Cinema and Mini Golf course at the top desk. They will pick up and drop off you at the hotel at Hanoi/Halong/Cat Ba. Price for 2 days 1 night is from 200 USD and from 300 USD for 3 days 2 nights on Era cruise.
- Rock Climbing if seeing the beautiful limestone karsts isn't enough for you, try climbing them. Cat Ba Climbing is the best place to rent gear and sign up for guided climbing tours. They run full and half-day trips with combinations of kayaking, climbing and cruising the less touristy karsts.
- Cat Ba Market at the northwestern edge of town. The seafood section should give you a reasonable idea of the less exotic, locally consumed varieties of seafood caught locally.
- Visit Viet Hai village offers the natural tour for those wanting to discover the real nature of Cat Ba. If you are a big fan of the green forest, the place is your perfect choice.
The market is the best place to buy most things. Tourist trinkets such as shell sculptures are sold at stalls on the easterly edge of the waterfront.
- Buddha Belly Restaurant, 94 đường 1/4 thị trấn, Cát Bà ("), . It's a vegetarian restaurant, charming hosts and very tasty. It also offers excellent day excursions to both the highlights of Cat Ba and off the beaten path locations such as Thien Long Cave, which is only accessible by a short boat trip. edit
- Phuong Nhung Restaurant, 184 1-4 Street, cat ba town ("). Family run restaurant, super nice people and very cheap. there is only one person cooking on the wok you can see from the street, so you might need to wait a little. edit
- Phương Phương Restaurant, 232, 1/4 street, cat ba town (near Nam Dương Hotel), ☎ 01687556989. The restaurant has views of the sea, serves Vietnamese food and Europen food.Airy space, at an affordable price. Be wary of very long wait. edit
- Lang Chai sea-food restaurant, 256, 1/4 Street, Cat Ba, Hai Phong, Cát Bà, Việt Nam, ☎ +84936516991, . 24 hours. Lang Chai restaurant is newly built in 2016. You can try many different kind of sea-food at really reasonable price. 10. edit
A dead scene in low season.
- There are a number of Sea View Bar establishments, much of a muchness.
- Oasis Bar, 228 1/4 street, Cat Ba town. Located in front of the Cat Ba Hotel, this friendly spot has just been renovated, sea view. is easily identified by the yellow bulbs outside bar, open till late. One of the ex-pats favorite joint, great fun every night. Free billiards, dartboard and big screen TV for movies and sports events ! Clients are also encouraged to play DJ from the bar's iTunes selection. The awesome drink menu, offering the coldest beers, drinks, and cocktails. Drinks range from cheap and massive to expensive and small. edit
- Noble House offers 2 for 1 cocktail and free pool.
- The Flightless Bird is the original bar on the island, run by a New Zealander and going strong for 15 years. The drinks menu includes reasonably priced imported bottles of wine from various parts of the world as well as a straight to the point cheap drinks section. Darts upstairs.
- Rose Bar, (50m up the street behind Noble House). Best Mojito in Cat Ba island. Western music, awesome drink menu, most cocktails 40,000. Brand new with a nice atmosphere, and a really helpful, friendly young owner. Pool table for free. Best cocktail prices in town, if you're sick of drinking beer all the time. Open until 2:00 AM, rare in Cat Ba. Free beer for women. 30,000 for a nitrous oxide balloon. edit
- sky bar Lang Chai restaurant (Cat Ba island), 256, 1/4 Nui Ngoc street, ☎ +84936516991, . 24 hours. Good view at cheap price. You can enjoy the view of Cat Ba town from the height. Located at the foot of the way to Cat Ba beach 1, Sky bar Lang Chai restaurant is your destination after long day adventure. edit
There are loads of hotels along the waterfront with little to distinguish them, though a couple has elevators if you are less mobile or are traveling with elders. A few hotels have more recently sprung up alongside streets away from the water. However, these don't appear to be any cheaper. When looking at rooms, you may pay more for a water view. Free WiFi is standard. Avoid anywhere that tries to "include" breakfast, which costs almost nothing and is probably of questionable quality anyway. Similarly, avoid anywhere that prices in dollars; ask for the price in dong. Decent conversion (December 2015) is 22,500 dong to a quoted dollar rate. In the off-season, everywhere is empty so will compete heavily on price; a huge room for two cost 125,000 ($6) on the water (February 2012). In the offseason do not pay more than $10 for a room.
Prices now start at $8, with the majority of hotels offering $10 for an AC room double occupancy. Some hotels have a non-AC room available for slightly less.
- My Ngoc, Cat Ba Islands (central, waterfront, near the big sign). New, elevator, huge rooms, one comfortable bed and one vietnamese style harder bed, very helpful, friendly staff $10/night during off season [Jan 2014], $8/night [Oct 2014] edit
- Sunflower One Hotel, Nui Ngoc St (central, just around the corner from the waterfront), ☎ 031 3888429, . Three star hotel, many rooms have sea views. It is often used with Ha Long Bay boat tours when an overnight stay is requested on Cat Ba island. It is a quality hotel with good food. It has wifi in rooms but can be somewhat unreliable. Its sister hotel Sunflower Two, which is often used with cheaper Ha Long Bay tours, is about 1km inland on the same road, and is not as nice. edit
- Song Chanh, 178 Duong 1-4, ☎ 0978366751. A great value hotel along the main strip in Cat Ba town. Very friendly staff who can also organise onward travel or tours around the island. Ask for Mr. Thuy, and go on the National Park trek with his uncle. double and twin rooms, low season $10/rm, high season $15/rm. edit
- Catba Green House (old name Hanoi Hotel), Cat Ba Islands (Located at 249 Nui Ngoc Street, 3 mins walk to the habour), ☎ +84946130808 [email protected], . Recently bulit hotel with clean room and good service, there may be some construction near by but it is not too loud. edit
- Hotel Phu Thanh, So 176 Duong 1/4, ☎ 0313696289 or 0976506999. New hotel only opened in 2009 with really nice, large, clean rooms. Has free wifi included and satellite flat screen TV. Good showers with hot water that actually have pressure. They also serve some great food in the restaurant during the busier summer months. Friendly staff and family owned and run. Rooms start at $10. edit
- Ngoc Hoa Hotel and Restaurant, 211 Duong (200m to the left of the dock), ☎ +84 16 4944 4024, . checkout: 12. Rooms facing the Bay, close to the ferry. Free wifi. Elevator. Fridge and aircon included. Family restaurant downstairs. Tours and scooters available at good prices if you ask, but the staff is not pushy. Their restaurant serves good simple Vietnamese food, soups, noodles, rice. Strong coffee and fruit smoothies. Big beer for under a dollar. 10-15$. edit
- Le Pont Hotel, 62-64 Nui Ngoc St, ☎ Mr. Jim +84 (0) 928 006 879. Dormitory $3.5 per person, rooms $4.5 per person, minimum two persons (April 2012). edit
- Monkey Island Resort (Monkey Island - Cat Ba islands), Monkey Island beach, ☎ 0316299888, . This resort is ideally located at Monkey Island beach in Lan Ha Bay. It is about 10 minutes going by boat from Beo harbour in Catba town. There are 29 rooms included 8 standard bungalows, 6 garden view bungalows, 6 deluxe sea view bungalows and 8 comfortable suite Seaview bungalows. There are spacious restaurant, game center for playing billiard, ping pong, table football, there are internet and wifi internet too. Kayaking, hiking the mountain and playing games here are free. edit
- Ngoc Khanh Hotel, 48 Đường Núi Ngọc st. (A bit further up the street, on the right side, near a small grocery store and a karaoke bar.), ☎ 091 468 99 00. probably the cheapest hotel in Cat Ba! Very clean, nice double and triple rooms for as little as 100.000 dong (Nov 2013). Big comfy beds with a soft mattress, nice bathroom with hot water, excellent wifi signal in some of the rooms near reception, not so good in the rear. Satellite tv, balcony, free pool table downstairs, cheap beers, honest and helpful staff although very limited English meaning you don't get hassled for tours and transport, laundry service. (Sept 2013) $5. edit
- mr zoom backpacker hostel (and restaurant), 25 nui ngoc thi tran catba (vietnamese food and sea food), ☎ 01649444024, . checkin: 07am; checkout: 12am. mr zoom freidly and helpful.good room very clean $6. (50m,200m) edit
- Sea Pearl Hotel, 219, 1/4 road, Cat Ba Island (opposide to Cat Ba Welcome gate on the left), ☎ 0313688567, . Sea Pearl Hotel located between the main roads of Cat Ba resort, beside dreamy Cat Ba Bay. The Hotel has 14 floors include restaurant, spa and bar, has started from 05/19/2011, The Hotel has got many attentions and supports from tourists and partners on around the world. It has 85 luxury rooms with elegant design bring up relax and comfortable feelings as second home for tourists. All front of Hotel is forward Cat Ba bay, behind the Hotel is room system with distant view cover all resort. edit
- CatBa Central Hostel Backpackers, 240 1.4 Street, CatBa Island (Bear right off the ferry terminal, along the harbor promenade (harbor to your right). The hostel is about 100m down in the leafy courtyard. Pickup from ferry/bus terminal can be arranged.). checkin: 12 Noon; checkout: 12 Noon. CatBa Central Hostel Backpackers is family run, offering 42 beds in clean and safe environment, with A/C. Breakfast menu as standard. Situated on the walking route to the main swimming beaches on the direct harbor facing promenade. US$7 Incl. Breakfast. edit
- Cat Ba Hostel, 160 Nui Ngoc St (Head up Nui Ngoc Street (the second one as you walk along the main drag towards the beaches) to near the top, number 160. Nice and quiet), ☎ +84 4977894883 ([email protected]), . Owner is a local Vietnamese guy called Hieu who speaks great english and is happy to help you out. One of the cheapest in town. Breakfasts are good too Dorm US$3, Private Room as low as $8 sometimes. edit
- Cat Ba Love Hotel, Cat Ba Islands (central, Nui Ngoc Road, near the main Pier ~ 100m), ☎ +84969671226, . checkin: 2PM00; checkout: 12PM00. New hotel (2015), rooms come with two double beds (4 persons max.), clean room, 4 floors, TV LCD, Free Wi-Fi, Hot Water, family owned USD 10-15/night depending on season 10-15 USD. (20.724606,107.052129) edit
- Lang Chai hotel, 256, 1/4 Street, Cat Ba, Hai Phong, Cát Bà, Việt Nam, ☎ +84827468889, . checkin: 8am; checkout: 12pm. 10. edit
To Hanoi, the easiest way to leave Cat Ba is through Bus + speedBoat + Bus. You can find these on the main beach road by the docks.
Leaving town, bus and boat to Hai Phong city (150,000 dong; almost hourly from 6AM to 4PM),takes about 1,5 hours. Also with high speed boat takes about 1 hour(220,000 VND/1 ticket, from 8 AM, 10 AM, 2 PM and last time 4 PM) are available from the square on the waterfront near the boat pier or HOAN TUYEN Travel office. Hotels can book tickets for you at a slight premium.
From Bến phà Tuần Châu harbor to Halong City : 150,000 VND.
From Ben Beo harbor to Halong City: 170,000 VND - 3hours - wonderful.
You can then go back to Hanoi by bus for 100,000 VND.
To Phong Nha
If you'd like to get to Phong Nha from Cat Ba head to the Hoang Long offices located inside the My Ngoc Hotel and ask for a bus ticket to Phong Nha. What you'll actually get is a bus ticket that says it's going to Quang Binh, which is the province in which Phong Nha is situated (cost between 400 and 500 VND). On the day of travel, you'll probably depart at 1pm from the Hoang Long office. From there you'll bus to the port, take a boat to the shore and be directed to a bus that takes you to the Hai Phong bus station. The sleeper bus leaves at 7pm so you'll have some time to kill. At around 6:30 they'll board you on to to the bus. The toilets are basic, obvious, and there are no official toilet stops on the way, so be prepared. There is also no food or drink available on the sleeper coach. The beds are small, if you're over 5ft 8in you'll be a little squashed.
The bus will drop you off in Dong Hoi at around 5 am on Ly Thuong Kiet about 1k east of the bridge which crosses the river. From there you're on your own. You can take a taxi (expect to pay 500,000 VND - if you can find a big taxi and enough fellow travelers this may be desirable) cheaper is the local bus (35,000 VND). To get the local bus head west on Thuong Kiet and turn left before the university (Truong Dai hoc Quang Binh) follow that road for about a kilometer (it takes you past the university and an ATM) and turn right on the first sealed road you see. That will take you to the main road called Huu Nghi. Turn left on to that road (don't cross over stay on the same side) and you'll see a bus stop, it's just a blue sign with a picture of a bus on it and the routes of various local busses. Take the B4 bus,( just flag it down when it arrives) which will take you up to Phong Nha. The bus conductor may "charge" you an extra 10,000 VND for your bag. Alternatively, you can head straight to the main bus station (Ben de Nam Ly) on Mac Dong Dung but it's another few kilometres.
Buses leaving the main terminal at 05:20, 06:00, 07:10, 08:00 and then on the hour every hour until the last bus at 17:00. So if you get in at 5am you can make the 05:20 if you're quick but most likely you'll get the 06:00. Keep in mind that those are departing from the main station if you follow the instructions above you're boarding after that so it may be 10 minutes later. You're also on Asia time, so it may not be running on schedule at all!