Around 1:30 pm Sunday, the vessel, "China Coast Guard 3411," reached waters in the vicinity of the spot where the plane was believed to have been when it lost contact with ground control, according to the country's marine police bureau.
The vessel relies on strong searchlights and night vision equipment to search around the clock in a wider area, said the latest statement from the bureau, adding that the search will take into account expert analysis on the sea area's currents and wind speeds.
Previously, the vessel found eight ships in the nearby waters and has contacted two Malaysian ships among the eight. They said they found nothing related to the plane.
"China Coast Guard 3411" has also contacted another Chinese vessel, "Tai Shun Hai," a business ship of the China Ocean Shipping (Group) Company which has been hunting for the plane in the search area for about five hours but has detected no clues.
All crew members on board the coast guard vessel are now working in six teams in charge of lookout, search, communication, medical treatment, motorboat rescue and logistic supplies, according to the administration.
Contact with the flight was lost along with its radar signal at 1:20 a.m. Beijing time on Saturday when it was flying over the Ho Chi Minh air traffic control area in Vietnam.