Nguyen Van Duc, 24, and Lao Van Quang, 28, are being held in custody.
Duc was arrested on charges of violating regulations on controlling means of waterway traffic and causing serious consequences in line with Article 212 of the Penal Code.
Duc, who had no licence for being in charge of a vessel, allegedly piloted boat 72K BD 0943, managed by the local Din Ky Tourism Company, carrying at least 26 people in a birthday party when the tragedy happened on the evening of May 20, due to strong wind accompanied by heavy rain. The tragedy claimed 16 lives, including four Chinese.
Quang was arrested on charges of assigning an unqualified person to control a means of waterway traffic, in line with Article 215 of the Penal Code.
Quang, as the manager of Din Ky Tourism Company, allegedly assigned Duc, who was a waiter on tourism boats and had no marine vessel licence, to drive boat 72K BD 0943.