Synonyms of underwater

underwater

adjective

ˌən-dər-ˈwȯ-tər 

as in aquatic

living, lying, or occurring below the surface of the water

underwater plants don't require as much light to grow as surface plants

a vessel designed for underwater exploration

Synonyms & Similar Words

• aquatic
• submarine
• submerged
• sunken
• oceanic
• undersea
• deep
• deepwater
• deep-sea
• abyssal
• abysmal

Example Sentences

Recent Examples of underwater

The handover of the INS Drakon is expected to significantly bolster Israel's underwater strike and reconnaissance capabilities, The Algemeiner reported. — Emma Bussey, FOXNews.com, 9 Aug. 2026

Also in the parade ranks were new uncrewed submersible vehicles – underwater drones, stealthy in their own right, that could pose a threat to any of Beijing’s adversaries. — Brad Lendon, CNN Money, 8 Aug. 2026

In 2022, Anduril expanded into undersea systems with the acquisition of Dive Technologies, whose autonomous underwater vehicles became the basis for its Dive-LD platform. — Encyclopedia Britannica, 7 Aug. 2026

The accurate and robust biometric sensors include an optical heart rate sensor, electrical heart sensor for ECG, altimeter, ambient light sensor, a compass, a gyroscope, an underwater depth gauge, and more. — K. Thor Jensen, PC Magazine, 7 Aug. 2026