MARIN, a maritime research institute in the Netherlands that conducted a simulation experiment with a model of the Sewol ferry for the hull investigation committee as well as the special commission, identified poor stability and cargo movement as reasons the Sewol ferry sank, dismissing the submarine collision theory.

The 2014 Sewol ferry disaster was caused by a fatal combination of illegal structural modifications, massive overloading, and steering errors. To increase profitability, the ship was renovated with extra decks that made it dangerously top-heavy. On the day of the sinking, it carried over twice its legal cargo limit, including unsecured vehicles and containers. When the ship made a sharp turn in the Maenggol Channel, the shoddily secured cargo shifted to one side, causing the vessel to list beyond recovery. Compounding the tragedy, only a fraction of the required ballast water was on board to save weight, which stripped the ship of its "restoring force." Nine official investigations have since led to over 150 arrests, uncovering a web of corporate corruption and regulatory negligence that prioritised profit over the safety of the 304 victims, most of whom were high school students.