A sailor looks back on a life of telling "great lies" aboard ships, then returns home only to find that the way there is "this very ash." The poem is very short, but it leaves a lot of room to think.
The lies could be stories told at sea, or something larger, like pretending to be a person he wasn't. Either way, the speaker seems to have lived inside them for a long time. When he finally turns back, nothing welcoming is waiting. Home is burned out, or perhaps it has simply crumbled into memory and loss. The poem doesn't say which, and judging by the imagery, that uncertainty is part of the point.
The title, "Sailor's knot," hints at something tied up and hard to undo, as if the lies and the return are knotted together. The mood is quiet, bare, and sad. There is no big outcry, just a calm recognition that the road back leads through what's left over.