Concerns have been raised over the military’s surveillance capability after a North Korean fishing boat was found adrift in South Korean waters, assumedly hours after it entered.

The North Korean fishing boat was found drifting some 150 kilometers below the Northern Limit Line in territorial waters of the South on Saturday. The boat, carrying four fishermen, was reportedly drifting after its engine broke. 

South Korean fisherman first spotted the boat near waters off Samcheok Port in Gangwon Province and reported it to local police at around 6:50 a.m.

As of Sunday, the four crew members were being investigated by authorities here. It has not been confirmed whether they wish to return to the North or to stay here.

It is not the first time a North Korean fishing boat has drifted below the NLL, the de facto maritime border. However, the surveillance systems of the military and coast guard have come under fire, as questions are being raised over why the boat was not detected before reaching so close to a port in South Korea.

The North Korean boat is reportedly 1 ton in size and made of wood. This may have made it difficult for surveillance systems to detect it, as they usually spot vessels of iron and steel properties.

In addition, experts say it is rare for such a small wooden boat to be able to travel such a long distance without capsizing.

On Tuesday, a fishing boat with six people was found around waters off Sokcho, Gangwon Province, some 5 kilometers below the NLL.

The Korean Navy had repatriated the crew members in the evening of the same day, as they had wanted to return to the North, according to South Korea’s Joint Chiefs of Staff. That fishing boat had also accidentally drifted into South Korean waters after its engine broke.

By Jo He-rim (herim@heraldcorp.com)