Very few visitors arrive at Hong Kong by sea and, as a matter of fact, unless you visit the territory with one of the cruises, the only destination you are likely to get to, by sea, is Macau.
Passenger sea services also connect Hong Kong with various towns on the Chinese side of the Pearl River Delta but as a visitor, you are not likely to find much interest in those mainly industrialized towns...
There are ferry services connecting Hong Kong with Shenzhen and Guangzhou but getting to these cities by bus might be faster and more convenient (especially if the bus drops you right where you want to go). The ferry's main advantage over the bus is that you don't have to go through the hassle of crossing the border (especially when the immigration and customs facilities of Hong Kong and Mainland China are located in two different buildings, which is the case in most of the border-crossing points)
Ferries depart from Macau Ferry Terminal, in Central, Hong Kong Island (Firectly linked to exit D of MTR-Sheung Wan), as well as from HK China ferry terminal in Tsim Sha Tsui, Kowloon (adjacent to Harbor City), and arrive at Shekou, some 30 minutes drive from downtown Shenzhen. There are quite a few ferries every day. The journey takes about one hour and a one way ticket goes for something like HK$ 100 - 150 (depends if it's day or night...)
Shenzhen Xunlong Shipping Co. and Shenzhen Pengxing Shipping Co. are the two major ferry operators on the Hong Kong - Shenzhen (Shekou) line.
For more information you can call their ticketing offices in Hong Kong:
Shenzhen Xunlong Shipping Co.
China Ferry Terminal, Tsim sha Tsui: (852) 2736 1387
Macau Ferry Terminal, Central, Hong Kong Island (852) 2858 0909
Shenzhen Pengxing Shipping Co.
China Ferry Terminal, Tsim sha Tsui: (852) 2730 3213
Ferries run between Hong Kong and Macau 24 hours a day, 7 days a week. They depart from two points in Hong Kong : the Hong Kong Macau Ferry Terminal on the island (not far from exit D of MTR-Sheung Wan) and from HK China ferry terminal in Tsim Sha Tsui, Kowloon (adjacent to Harbor City).
Shun Tak - China Travel Ship Management operates the Turbo Jet, quick ferry service to Macau, as well as to Shenzhen.
Their ferries to Macau leave every fifteen minutes during the day, and every thirty minutes at night. Travel time is slightly less than an hour and the price ranges around HK$ 140 per person, one way (prices are slightly higher at night, as well as on weekends).
The company also operates Turbo Jet ferry lines from Hong Kong International Airport to both Macau and Shenzhen. For more information and bookings : www.turbojet.com.hk
First Ferry Macau also operates ferry services that connect Hong Kong with Macau. Their ferries depart from Tsim Sha Tsui every thirty minutes, from 7 am till midnight. Travel time is slightly more than an hour and the price ranges around HK$ 140 per person, one way (Economy class).
For more information and bookings : www.nwff.com.hk
For those of you who only want to visit the Cotai Strip and the Venetian, the new CotaiJet service might just be the right thing. The jet ferry departs from Tsim sha Tsui's HK China Ferry Terminal, in Hong Kong, and travels to Taipa Island's Temporary Ferry Terminal in Macau (from where a free coach takes you to the Cotai Strip).
Ferries depart daily, every thirty minutes (every one hour at night), from 7 am to 1am. Traveling time is one hour and the basic fare is HK$ 134 one way (HK$ 146 on weekends and holidays and HK$ 168 for the night service). From Macau, ferries leave every thirty minutes (every one hour at night, and every two hours late at night...), from 7:30 am to 5am (which means you can party the night away in the Venetian and make it back to Hong Kong, just in time for breakfast...)
For more information and bookings : visit the Cotai Jet website.
CKS operates fast ferry service that connects Hong Kong with different towns on the Chinese side of the Pearl River Delta. The ferries depart from Hong Kong Island and Kowloon, as well as from Hong Kong Airport's Sky Pier.
For more information and bookings (including destinations map, timetables and fares) : www.cksp.com.hk