Such a boat is fit only for a calm sea.

这种船只适于在风平浪静的海上航行。

《新英汉大辞典》

Such a boat is only fit for a calm sea.

这种船只适合于在风平浪静的海上航行。

youdao

You're always calm but also driven by a deep-rooted desire to improve and perfect everything around you. Sweden would be the perfect fit for someone like you.

你总能保持淡定，同时又有一股来自内心深处的渴望，希望能让周围的一切都更好更完美。瑞典最适合你这样的人。

youdao

Mr Hollande's calm and consensual manner could be a better fit for Mrs Merkel's temperament than Mr Sarkozy's impetuousness.

ECONOMIST: Charlemagne

Journalists bandy the term "an uneasy calm" around quite a lot, but it seems a perfect fit to describe the mood here.

CNN: Fear, despair as bailed out Cyprus faces uncertain future