On the surface of it, this poem describes the sea and its endlessness. Hughes describes the sea as a "wilderness" and a "desert," both words which are usually applied to dry land, and both of which suggest a certain barren emptiness. A wilderness and a desert are both places devoid of people and things: to be in such a place is to be alone. Hughes repeats the two opening lines of the poem at the end of it, the parallelism serving to enclose the message of the poem and reinforce this sense that the sea is overwhelmingly vast.

The title of the poem—"Long Trip"—and the references to "we" in the poem suggest that, rather than simply being literally about the sea, Hughes may actually be using the sea as a metaphor for life. It is unlikely that a person would spend "day, night, / Night, day" actually on the water, yet these two lines suggest a monotony of experience: "we" have been on this sea forever. On it, we "hide and are hidden"; it is our whole universe and our reality. Sometimes we "dip"—when things seem to be going downhill for us—and at other times, we "rise." Yet, ultimately, the sea goes on forever and we are alone in the "wilderness" of it, left to ride its waves, just as we go through life alone, subject to its unpredictable vicissitudes.

Langston Hughes' poem "Long Trip" is a very descriptive poem which describes the ocean. The language Hughes' applies proves to be image ridden and filled with motion (like the water described in the poem). 

Meaning of a poem varies from reader to reader. What one reader may take from a poem may be very different from what another reader takes form the same poem. 

For some readers, the meaning of the poem is positive. The open ocean surrounds the speaker and the reader (denoted by "we"). Others may define "we" as the speaker and another passenger on the water vessel the two are on. The water moves rhythmically (just as the poem does). The poem's intent (or meaning) is to soothe. 

On the other hand, other readers may look at the poem negatively. The two on the open water are lost, left to the mercy of the rolling water. There is no hope for the two upon the water (denoted by "day, night / night, day"). They are lost. Here, the meaning of the poem is hopelessness (the two are lost in a "wilderness of water").