вартовий / чатовий біля входу
sentry go / sentry-go
group sentry post
pick off a sentry
sentinel / sentry
air sentry
border and offshore submersible sentry
zone of sentry guard
boom barrier (boom gate)
stern gate
boom gate
visible gate
flux gate detector
gyro flux(-)gate compass
gyro stabilized flux(-)gate compass
gate change
gate
gate a target in range
gate pulser
narrow gate
narrow gate pulse
narrow-narrow gate
narrow-narrow gate pulse
sea chest gate valve
swinging gate principle