TAIPEI (Taiwan News) — A new map by the National Academy of Marine Research (NAMR, 國家海洋研究院) led netizens to comment that large submarines would find it difficult to approach and leave Taiwan, reports said Tuesday (Nov. 16).

The map showed the geography of the bottom of the oceans and sea straits surrounding Taiwan, with all the canyons and troughs in between the more elevated areas, the Liberty Times reported.

The findings helped to understand how over 6 million years, Taiwan acquired peaks nearly 4,000 meters tall, with depths of 6,000 m to the east, the NAMR said. On the western side, the Taiwan Strait is on average 60 m deep.

Netizens interested in military issues drew the conclusion that the vast differences in depth around Taiwan pose problems to larger types of submarines, according to the Liberty Times report. Because of their size and due to the uneven terrain, the vessels might find it difficult to move close to Taiwan and to escape during times of war, commentators reportedly said.