The Sewol ferry that sunk April 16 exceeded its cargo limit on 246 trips, almost every trip it made, in the last 13 months, according to documents. And on its final, doomed voyage, it may have been overloaded more than ever.

Two different entities were in charge of recording the weights and setting the weight limits. The two companies did not communicate with each other. This failed system left more than 300 either missing or dead.

With the sinking of the Sewol, South Korea's poor monitoring of domestic passenger ships has been exposed. Country regulators had enough information to know that the Sewol was frequently overloaded, but since this information was not communicated, the information was useless.

When the Sewol was being redesigned early last year to handle more passengers, the Korean Register of Shipping examined the vessel. They said the ship had to reduce its cargo capacity by more than half to 987 tons. It also said the ship needed to carry more than 2,000 tons of water to remain balanced.

This information only made it to the ship's owner Chonghaejin Marine Co. Ltd and not the coast guard or the Korean Shipping Association. The shipping association oversees passenger ships' arrivals and departures, but they did not know about these new limits placed on the Sewol's cargo.

"That's a blind spot in the law," said Lee Kyu-Yeul, professor emeritus at Seoul National University's Department of Naval Architecture and Ocean Engineering. 

Chonghaejin told the shipping association it had a capacity of 3,963 tons, according to a coast guard official in Incheon.

Since the Sewol's cargo capacity was greatly reduced down to the 987 ton number, it has well exceeded that number over 100 times. There were 136 instances where the ship reported over 2,000 tons and 12 instances where the ship reported over 3,000 tons of cargo. 

On the day of the tragic sinking, an estimated 3,608 tons of cargo was loaded onto the ship according to Moon Ki-han, vice president at Union Transport Co., the company that loaded the ship.

Since passenger ships don't have to report their cargo until after their voyages are completed, the port operator had no record of how much the Sewol was carrying.

Paperwork filed by the Sewol's captain before the final voyage reported a much smaller load. He reported 657 tons of cargo and 150 cars on the ship. 

That's clearly a false report. Investigators have already found 180 cars in the water.

"The only person on any vessel who knows the exact cargo safety limit, excluding ballast water, fuel, passengers and others, is the first mate," an official with the Korean Shipping Association's safety team said.

After the disaster, all 15 of the surviving crew members have been arrested for negligence and failure to protect passengers.

The cause for the sinking is still under investigation, but it's highly likely that it is due to severe overloading.

The ferry operator "was trying to make a profit by overloading cargos," said Kim Gil-soo, a professor at Korea Maritime and Ocean University in Busan, "and public agencies that should have monitored did not monitor that."