Vietnam spends $1B to build Southeast Asia’s third-longest sea bridge

Vietnam has unveiled plans for its longest sea-crossing bridge, an 18-kilometer span linking Ca Mau Province to Hon Khoai Island, a rugged outpost at the nation’s southern tip that has long been closed off as a military zone.

The project, launched on Aug. 19, will be built to international sea-crossing standards with four lanes and a design speed of 80 kph. At an estimated cost of VND25.7 trillion ($1 billion), the bridge will rise from the Ca Mau–Dat Mui Expressway and extend across open sea before touching down on the forested granite slopes of Hon Khoai. Completion is expected by the end of 2028.

Construction will be handled by Army Corps 12 under the Ministry of National Defense, using a combination of bored piles and steel pipe foundations for the deep-water areas. Its navigational span will employ a 150-meter steel arch, a feat of engineering that will place the structure among the longest and most advanced sea bridges in Southeast Asia.

The Hon Khoai project does not stop at the bridge. A vast deep-water port is also being built on the island, including a 1,000-meter berth capable of receiving ships of up to 250,000 DWT and handling 20 million tons of cargo per year. Once fully developed, the port will expand to 686 hectares with additional container, liquid and gas terminals. In tandem, the 80-km Ca Mau–Dat Mui Expressway, with a design speed of 100 kph, is also scheduled for completion in 2028.

When finished, these three mega-projects: the bridge, the port, and the expressway will create seamless connectivity from Vietnam’s northern border all the way to its southernmost tip. The development will not only fuel economic growth through trade and tourism but also strengthen defense and security in a region that sits directly along key international shipping routes.

At 18 km, the bridge will dwarf the current record-holder, the Tan Vu–Lach Huyen Bridge in Hai Phong (5.44 km, opened in 2017), and easily surpass Quy Nhon’s Thi Nai Bridge (2.5 km).

That would make it the longest sea-crossing bridge in Vietnam and the third-longest in Southeast Asia, behind Brunei’s Sultan Haji Omar Ali Saifuddien Bridge (30 km) and Malaysia’s Sultan Abdul Halim Muadzam Shah Bridge (24 km), according to the Southeast Asia Iron and Steel Institute.

Hon Khoai itself is a small but striking island, just 28 km offshore, with its highest peak reaching 318 meters above sea level. Covering about 4 square kilometers, the island has remained uninhabited except for military personnel.

Pham Thanh Ngai, chairman of the Ca Mau People’s Committee, said the province is the only one with three sides bordering the sea. Hon Khoai in particular lies right at the frontline, facing international shipping lanes.

Ngai believes Ca Mau’s strategic location, at the very heart of Southeast Asia’s maritime routes, makes it an ideal site for a deep-water port and a symbolic new gateway to Vietnam’s southern frontier.

By Chuc Ly – VnExpress.net – August 20, 2025