Nguyen Nhat Minh had booked a ticket worth VND1.1 million (US$43.14) for the most expensive class to experience the vessel on May 15.
He said the services and amenities on the country’s largest passenger vessel were great but the road from downtown area to Hiep Phuoc Port where the vessel departs was far, causing inconvenience.
In addition, passengers must pay a fee to enter and leave the port, he said.
Le Thanh Hang, living in Ho Chi Minh City, said if she took a taxi from the port to her home in District 8 that costs VND400,000, it would be nearly equivalent to the economy-class ticket price.
The trip she took in mid-May was empty, with many available seats in the front and back rows.
Vu Van Khuong, general director of Phu Quoc Express Boat Company, its operator, said that the number of passengers per trip was less than 50% of capacity.
The vessel can take 1,017 passengers and each trip was expected to reach 80% capacity on weekdays and 100% capacity on weekends, but each trip had only 300-400 passengers on average, Khuong added.
He said the company had difficulty in transferring passengers from the city center to Hiep Phuoc Port and the long distance had prevented passengers from using the service.
The company's personnel mainly work in maritime activities, but now must take on road transport work, "so there are still many inadequacies," he added.
Previously, the company had offered free shuttle bus service to transfer passengers from the city center to the port but many passengers registering to use the service made last-minute cancelations, causing losses to the company.
Khuong expects the number of passengers traveling on the boat to increase during the peak summer season, with 500 passengers on weekdays and 700 on weekends.
The vessel was launched on May 13 and makes three trips a week every other day.
It leaves Hiep Phuoc Port at 7 a.m. and Con Dao's Ben Dam Port at 1 p.m.
Tickets, sold by agents and at ticket offices and websites, cost VND615,000 - 1.1 million (US$24-43) depending on ticket class and departure time.