By Boat/Bus -- Most visitors get to Cat Ba on tours through Hanoi's budget cafes. The typical boat journey includes an exploration of Halong Bay and an overnight on the island, but more and more folks are now booking their boat journey through Halong with a tour company, then ending the trip in Cat Ba and taking the reigns from there. You might even arrange a stop in Haiphong or onward to Ninh Binh.
New on the scene, with a very fast bus-to-boat service, Hoang Long Bus Company (in Hanoi, 28 Tran Nhat Duat, tel. 04/3928-3720; in Haiphong, 11 Tran Nguyen Han, tel. 0313/700-778; on Cat Ba Island, tel. 0313/887-224) runs four times daily from Cat Ba back to the mainland at Haiphong and on to Hanoi. They have air-conditioned buses that pick you up and whisk you to the dock of a high-speed ferry. Departure times from Hanoi start at 4:50am and run every 30 minutes; the last departure is at 9pm. From Haiphong, boats start at 6:05am and the last one leaves at 9:05pm. Return tickets will set you back 60,000 VND.
A high-speed ferry also leaves from the pier at the town center every half-hour between 7am and 5pm. The cost is 90,000 VND. Contact Thuong Nhat Transport Cooperative (cosponsored by Vietnamese and Japanese) through the folks at the Sunflower Hotel (Nui Ngoc Rd., just 20m/66 ft. off the seaside boulevard; tel. 0313/888-429), where they can arrange a ticket.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.