The Karnaphuli Tunnel in Chattogram, Bangladesh’s first underwater tunnel, has started generating profit after several months of losses. Initially struggling due to low traffic, the tunnel now benefits from a privately-operated dry dock across the river, which has increased cargo and vehicle flow. Daily toll revenue has risen to Tk 400,000–500,000, with prospects for further growth as more jetties become operational. Faster cargo movement via the tunnel reduces congestion and import costs, marking a major turnaround for the Bangladesh Bridge Authority.