Every surfer, at some point in their wave-riding career, has closely examined a strange, unwieldly accumulation of water and wondered: Can it be ridden? A new video from Vietnam's Lòng Tàu River poses exactly that question. The footage follows the HUA HENG 167, a 623-foot cargo ship sailing under the Chinese flag, as it carefully threads its way through the river's narrow, winding shipping channel southeast of Ho Chi Minh City. The vessel's sheer size leaves little room for error, requiring slow, deliberate maneuvers as it navigates one of Vietnam's busiest maritime corridors. But it's what happens surrounding the ship that sparked surfers' curiosity. As the massive freighter pushes millions of gallons of water aside, it generates long, peeling displacement waves that fan across the riverbanks. While hardly ocean swell, the wakes are surprisingly clean and organized, rolling for hundreds of yards before dissipating downstream. In several moments, they look tantalizingly surfable.…