One out of four shuttle ferries operating in coastal waters here are over 20 years old.
The Ministry of Oceans and Fisheries on Sunday said 173 ferries operate 95 coastal routes at the moment and 42 are at least 21 years old. Sixty-three are between 16 and 20 years old.
Seventeen were bought second-hand from Japan like the Sewol.
The main reason there are so many aged ferries is that the government has steadily relaxed the age limit since the 1990s.
From 1984 to 1991, the age limit on ships operating on coastal waters was 20 years. The Sewol, which was built in 1994 is 20 years old this year, so it would have been for the scrap yard.
But the limit was raised to 25 years in 1991, and in 2009 guidelines were relaxed even further to allow ships up to 30 years old to operate provided they pass annual safety tests.
"The cost of building passenger ferries is a lot for small operators to bear," a ministry official said. "That's why we loosened the regulations."
Some Japanese netizens are wondering why Korea, a strong shipbuilding nation, is buying second-hand ferries from Japan. But a ministry official said the Korean ferry industry is very small, with an average of just 2.7 ships per operator, so the Korean shipbuilding industry is strong on big commercial ships but not on ferries.