Suspicious seacraft. The DPRK (North Korea) especially has a habit of iilegally trespassing into Japanese waters.

search (rescue of a missing person etc.) / investigation (police investigation)

search (especially for a missing person or people) / investigate

to start; to begin; to initiate

start; beginning; initiation

being suspicious, being doubtful, being questionable, strangeness

suspicious, strange, dubious

ship, vessel, larger ship

Short for 警察署 (keisatsusho, “police station”). / police

ship, vessel, larger ship