How to say "waters" in Japanese

• 海うみJLPT N5approx.Common
  nounThe ordinary word for the sea or ocean; it matches 'waters' when English uses the word for the sea itself, as in talk of coasts, voyages or the open sea.
  何なんとしても海うみをひと目めみたいものだ。↗

  I ache for a sight of the sea.
• 水域すいいきCommon
  nounA word for an area of water as such, rather than the sea in general; it suits 'waters' in geographic or scientific descriptions of a particular body or stretch of water.
  海うみの氷こおりはきわめて変かわりやすい――寒さむく風かぜのない天候てんこうのときは固かたく凍こおっているが、嵐あらしのときは外洋がいようの広ひろい水域すいいきで割われてしまう。↗

  The sea ice is highly variable - frozen solid during cold, calm weather and broken up in large areas of open water during storms.
• 海域かいいきCommon
  nounA word for a particular area or region of the sea; it fits 'waters' when a specific stretch of sea is meant, as in geographic descriptions and news reports about a given sea area.
  この海域かいいきを航行こうこうするのはとても気持きもちがいい。↗

  It is very pleasant to sail these waters.

Use 海 for the sea itself, 水域 for an area of water in general, and 海域 for a defined region of the sea, as in geographic or news contexts.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 海うみsea
• 水域すいいきwaters
• 海域かいいきarea of sea
• 水霜みずじもwaters (i.e. amniotic fluid discharged shortly before birth)