Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why
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Acts 27:28

They took soundings and found twenty fathoms. After a little while, they took soundings again, and found fifteen fathoms.

Parallel Translations

KJVView canonical →
And sounded, and found it twenty fathoms: and when they had gone a little further, they sounded again, and found it fifteen fathoms.
King James Version