Once a day the rocks， with little warning-

    not much looked for even by the spruce

    and fir ever at attention above-

    fetch up on these tidal flats and bars.

    Large. crate-like rocks， wrapped in kelp；

    layer on imprinted layer，

    umber to claret to olivegreen

    of scalloped marbling. . . .

    Not far along the path of obstacles

    and stepping stones considered，

    fluid skeins of bladder wrack

    lie tufted over the mussel shoals-

    the seabed black as a shag's neck，

    a half-acre coalfield， but alive.

    Recklessly multiple， myriads compact，

    the small airtight coffers （in chipped enamel）

    are starred over with bonelike barnacles

    that crackle and simmer throughout the trek，

    gravel-crepitant underfoot.

    Evening comes now not with the Evening

    Star， but with a breathing fog.

    And fog is the element here，

    a new term， vast by indefinition，

    a vagrant damping of the deep tones

    of skies and bars and sea.

    Sand， mud， sand， rock； one jagged pool

    basining a water invisible

    except as quick trembles

    over algal weed-itself

    half-absent， a virid gel.

    Walking means to lose the way

    in fog， the eye drawn out to a farther point，

    a dark graph on the faint blue inlet watershine；

    out to where a heron stands，

    stationing its sharp silhouette

    against the fogbright dusk.

    Then， not to be approached，

    lifts off and rows upward， up， up，

    a flexible embracing-forward on the air，

    rising out of view

    behind an opaque expanse of calcium flame.

    The great kelp-dripping rocks，

    at random positions，

    lost in thought and dematerializing

    with the gray hour，

    release， indelibly， their pent-up contents.

    -Even the scattered feathers here

    are petrified， limewhite blades and stony down.

    The sky， from eastward， deepens

    with the dawning insight

    as the seas begin to rise， the flats

    slide away， the hulls bear off the ground，

    and the eye alien to so self-sufficing

    a tidal system turns and takes up how to

    retrace the steps that brought it there