Longman Dictionary of Contemporary English
sea power
noun
EXAMPLES FROM CORPUS
▪ For Mahan sea power was critical, for Mackinder a particular land mass.
▪ In a sea power economy, vested interests are in open markets and free trade.
▪ The most difficult strategic question was whether sea power was any longer the foundation upon which the Three Pillars could continue to stand.
WordNet
sea power
n. naval strength
a nation that possesses formidable naval strength