noun which may take the genitive case particle 'no'
anti-submarine
Used as a pre-noun modifier in military and naval contexts, often in compounds like 対潜水艦戦 (anti-submarine warfare) or 対潜水艦ミサイル (anti-submarine missile).
その艦は対潜水艦任務に就いている。
The ship is on an anti-submarine mission.
対潜水艦戦の訓練が行われた。
Training for anti-submarine warfare was conducted.
Abbreviation of 対潜水艦, used in the same contexts but more compact and common in technical or military jargon.
Compound of 対 (たい, 'against') + 潜水艦 (せんすいかん, 'submarine').