A Shadow Boat

Under my keel another boat
Sails as I sail, floats as I float;
Silent and dim and mystic still,
It steals through that weird nether-world,
Mocking my power, though at my will
The foam before its prow is curled,
Or calm it lies, with canvas furled.

Vainly I peer and fain would see
What phantom in that boat may be;
Yet half I dread, lest I with ruth
Some ghost of my dead, past divine,
Some gracious shape of my lost youth,
Whose deathless eyes once fixed on mine
Would draw me downward through the brine!