BLM_Fathom

In this sense a fathom has two meanings, the first is the literal meaning of fathom. A fathom is a unit (1.8288 meters.) used for measuring the depth of a given body of water. In this sense, the author is trying to express that the ocean is vast and mysterious. The second meaning coveys a similar message. In this meaning, fathom represents understandment symbloizing that the sea is something beyond human comprehension.