Aqua-Lung
air cylinder
aquascope
bathyscaphe
bathysphere
benthoscope
diving bell
diving boat
diving chamber
diving goggles
diving helmet
diving hood
diving mask
diving suit
scuba
snorkel
submarine
swim fins
wet suit
optical instrument
periscopic
periscopically
'scope
binocular
eyepiece
microscope
radarscope
spectroscope
telescope
polariscope