The speaker imagines building a small cottage by the sea, and the whole poem is a wish rather than a plan. The setting is vivid and ordinary: lobster traps stacked against a green fence, an old willow nearby. But the house itself is made of sea wrack and sea foam, materials that wash up, drift, and disappear. It is painted "the color of islands" and flashes like a gull's wing, so it seems half real and half made of light.
What the speaker wants is escape. The phrase "lost to the world of plans and contingencies" suggests tiredness with schedules, worries, and constant preparing for what might go wrong. In the cottage, time can be "wiled" away, spent slowly and without guilt. The speaker would spend it "carefully sculpting my stories," a quiet, patient kind of work.
The mood is dreamy, gentle, and a little playful. The last line, "becoming a legend," is half joking and half sincere, as if the speaker knows this is fantasy but enjoys it anyway.