OVERVIEW: Naval smoke grenades are handheld or launcher-fired pyrotechnic devices adapted for use aboard small military ships to lay visual and infrared smoke screens. They provide rapid concealment, signaling, or targeting assistance.

DETAILS: These grenades consist of metal canisters containing hexachloroethane (HC) or terephthalic acid (TA) smoke-producing mixtures and are typically ignited via a pull-ring fuze. Burn time ranges from about 70 to 150 seconds depending on composition, producing dense white, colored, or gray smoke that can obscure the ship from visual or IR detection. Some navies also use funnel‑injection systems—burning extra fuel or spraying chemicals to generate broader shipwide screens. Mounted smoke-grenade launchers in 76 mm or 82 mm calibers allow for targeted smoke deployment around the ship’s perimeter.

FONCTION:
Activated or fired to deploy smoke near the ship's hull or superstructure.
Smoke obscures visual and IR signatures, masking movement or position.
Can complement other obscurants (e.g., funnel smoke, chemical generators) for broader screening.

SOURCE:
Wikipedia – “Smoke grenade” ; Wikipedia – “Smoke screen” ; Bosamar.com – “FS smoke screen generators” ; NERO Industry – NU‑40SGLS launcher data