"Parting at Morning" is a sequel to Robert Browning's "Meeting at Night." Both poems describe a meeting between two lovers, one of whom appears to be a sailor. The first poem shows the lovers meeting for a sexual encounter, while the second shows their inevitable separation with the morning.
"Parting" is about the end of the tryst. The lovers are interrupted by nature itself (the sun coming up and the rush of the ocean), signalling that their separation is inevitable. It does not take long to discover why with the last line, which has the speaker saying he must go back to "a world of men," the sailor must return to a life where no women are ever present on-board the ships. This last line also suggests the identity of the speaker is the male lover.
What is interesting is that there is no melancholy in "Parting." Unlike, say, Romeo and Juliet, where the lovers mourn that night must give way to day, the speaker accepts the coming of the sun and the parting from his love. He feels his place is on the sea.