periscope
Submarine viewing tube
A periscope is an optical instrument with mirrors or prisms that lets you see things not in your direct line of sight.
The classic periscope is used in submarines to view the surface while submerged: The captain raised the periscope to scan for enemy ships.
Periscopes also appear in tanks and trench warfare, allowing observation while staying protected.
Light-focusing curved glass
- prismLight-splitting optical element
- mirrorReflective viewing surface
- refractionWave bending between media
- eyepieceLens you look through
magnification · focus · reticle · diopter · field of view · resolution · clarity · image
Systematic observation of subjects
- reconnaissanceInformation-gathering before action
- scanBrief visual sweep
- surveySystematic data collection
- spyCovert information gatherer
detect · spot · monitor · watch · sight · glimpse · peer · horizon
Lift or increase
- lowerReduce or move downward
- retractWithdraw something said
- telescopingSliding sections that compact
- extendMake longer or larger
rotate · elevate · deploy · hoist · collapse · hydraulic · mast · tube
Vehicles under unified command
- destroyerOne that ruins completely
- carrierOne that transports
- frigateMedium-sized naval warship
- battleshipArmored naval capital vessel
cruiser · corvette · minesweeper · warship · torpedo · admiral · commander · ensign
Intentionally concealed
- concealmentAct of hiding something
- submergedBelow water's surface
- hiddenKept out of sight
- undetectedNot discovered yet
clandestine · unseen · low profile · surface · exposure · detection · camouflage · silent running
Submarine's raised control structure
- U-boatUndersea warship from Germany
- submersibleUnderwater exploration vehicle
- snorkelUnderwater breathing pipe
- hatchOpening in deck or floor
pressure hull · ballast tanks · depth charge · diesel engines · nuclear reactor · hydroplane · sail · bridge
lens
Light-focusing curved glass
- prismLight-splitting optical element
- mirrorReflective viewing surface
- refractionWave bending between media
eyepiece · magnification · focus · reticle · diopter · field of view · resolution · clarity · image · ocular
surveillance
Systematic observation of subjects
- reconnaissanceInformation-gathering before action
- scanBrief visual sweep
- surveySystematic data collection
spy · detect · spot · monitor · watch · sight · glimpse · peer · horizon · bearing
raise
Lift or increase
- lowerReduce or move downward
- retractWithdraw something said
- telescopingSliding sections that compact
extend · rotate · elevate · deploy · hoist · collapse · hydraulic · mast · tube · housing
fleet
Vehicles under unified command
battleship · cruiser · corvette · minesweeper · warship · torpedo · admiral · commander · ensign · midshipman
covert
Intentionally concealed
- concealmentAct of hiding something
- submergedBelow water's surface
- hiddenKept out of sight
undetected · clandestine · unseen · low profile · surface · exposure · detection · camouflage · silent running · depth
conning tower
Submarine's raised control structure
- U-boatUndersea warship from Germany
- submersibleUnderwater exploration vehicle
- snorkelUnderwater breathing pipe
hatch · pressure hull · ballast tanks · depth charge · diesel engines · nuclear reactor · hydroplane · sail · bridge · keel
- submarinessub, subs, torpedo, submarines, hull
- Tank warfaretank, tanks, main battle tank, MBT, heavy tank
- optical instrumentsbinoculars, spectroscope, spectrometer, magnifying glass, lens
- submarine warfaresubmarine, submarines, torpedo, U-boat, sonar
- Undersea Techsubmarine, submersible, ROV, underwater drone, underwater robot
- tank partsturret, treads, cannon, hull, tracks
periscopenaked eye
Vision without optical instruments
direct observation · window · clear view · unobstructed view · binoculars
periscopeobservation tower
Elevated structure for viewing
watchtower · crow's nest · lookout post · observation deck · conning tower