The first new-type patrol ship F91 that China plans to export to Nigeria has been launched. It will be delivered in the middle of 2014 as scheduled. It will become the first ship of the Nigerian navy's P18N project. During an interview, Major General Yin Zhuo made particular mention of the vessel's stealth performance.

The first F91 stealth patrol ship was successfully launched on January 27. Its major missions include patrolling and guard duties along the coastline, protecting exclusive maritime economic areas, carrying out marine search and rescue, and preventing marine pollution. According to relevant data, the F19 patrol ship has a full length of 95 meters and a waterline length of 89 meters. With two diesel master engines, and a top speed of about 39 km/hour, it can navigate on the sea for 20 consecutive days.

On the stealth performance of F91, Yin Zhuo pointed out that the ship's bows lean slightly inward, and bevels are superimposed on the upper part of the deck; as a result, the radar reflection points are few and the radar image is small. He pointed out that an 1,800-ton ship with stealth capacity will have the radar reflection area of a ship of about 500 tons; it can be discovered only when it is very close to the radar of enemy, and cannot be observed if an appropriate distance is kept from the enemy radar.

Modern terrorists have a growing capacity for counter-reconnaissance and a strong combat capacity. While at sea, some can seek out nearby military ships patrolling in search of them. Therefore, the stealth performance of F91 is also essential for coping with non-traditional security threats.