Translation guide
The highest level reached by water, or metaphorically the peak of achievement or success.
The highest point reached by a body of water, such as a river, lake, or tide.
Standard technical term for the highest water level recorded or reached.
この川の最高水位は去年記録されました。
The high-water mark of this river was recorded last year.
Specifically the high-water mark of a tide, the line left on the shore.
砂浜に満潮線がくっきりと残っていた。
The high-water mark was clearly visible on the sandy beach.
A more general term for high water level, used in some contexts but less common than 最高水位.
高水位のため、堤防が決壊した。
The embankment collapsed due to the high water level.
The highest point of success, performance, or development in a non-physical sense.
Literally 'highest point reached', used for career peaks, record highs, or best achievements.
この作品は彼のキャリアの最高到達点だ。
This work is the high-water mark of his career.
Refers to the peak period of one's powers, popularity, or success. Often used for artists or athletes.
彼女は90年代に絶頂期を迎えた。
She reached her high-water mark in the 90s.
Loanword from English 'peak', very common in casual and business contexts.
最高水位 is the general term for the highest water level in any context (rivers, floods, etc.), while 満潮線 specifically refers to the high-tide line on a shore.
洪水の最高水位は堤防を超えた。
The flood's high-water mark exceeded the levee.
満潮線には貝殻がたくさん落ちていた。
There were many shells along the high-water mark.
ピーク is very common in everyday speech for describing the peak of anything (popularity, performance, stress). It can be used with に達する (to reach a peak) or as a noun modifier (ピーク時).
観光客数は夏にピークに達する。
Tourist numbers reach their high-water mark in summer.
壁の最高水位の跡で、洪水の深さがわかった。
The high-water mark on the wall showed how deep the flood was.
あのアルバムは80年代ロックの最高到達点だった。
That album was the high-water mark of 80s rock.
Sales hit their high-water mark last year.
Literally 'highest tide', used figuratively for the climax or peak of excitement, activity, or a story.
祭りは最高潮に達した。
The festival reached its high-water mark.