Berean Study Bible
but when they saw Him walking on the sea, they cried out, thinking He was a ghost—

King James Bible
But when they saw him walking upon the sea, they supposed it had been a spirit, and cried out:

American Standard Version
but they, when they saw him walking on the sea, supposed that it was a ghost, and cried out;

Darby Bible Translation
But they, seeing him walking on the sea, thought that it was an apparition, and cried out.

Douay-Rheims Bible
But they seeing him walking upon the sea, thought it was an apparition, and they cried out.

English Revised Version
but they, when they saw him walking on the sea, supposed that it was an apparition, and cried out:

Young's Literal Translation
And they having seen him walking on the sea, thought it to be an apparition, and cried out,