Kamojimono ukine o sureba minanowata kaguroki kami ni tsuyu zo okinikeru

鴨じもの浮寝をすれば蜷の腸
か黒き髪に露ぞ置きにける

Roma-ji: Kamojimono ukine o sureba minanowata kaguroki kami ni tsuyu zo okinikeru
English Translation: Like the wild duck
I sleep floating on the sea,
and on my hair,
black as the innards of a snail,
the dew has settled
Meaning: Sleeping afloat on the sea like a wild duck, I find the dew has settled on my hair, black as the innards of a river snail.
Commentary: Book Fifteen Poems of the Envoys to Silla 3649

Headnote continued from the preceding poem: "In the sea off Saba we suddenly met a contrary wind and drifted on swelling waves. After a night had passed we happily found a fair wind and reached Wakuma Bay in Shimotsumike District, Buzen Province. Recalling the hardship with pain and sorrow, we composed eight poems"
Sleeping afloat on the sea like a wild duck, he finds the dew has settled on his black hair. The hardship of spending the night aboard a ship with no roof is caught in the concrete image of dew lying on his hair. The simile of the duck sleeping afloat overlays his own uncertain lot, adrift on the water.
According to the headnote, this is one of eight poems composed by the travelers recalling their ordeal: in the sea off Saba in Suō Province they suddenly met a contrary wind and drifted, and after a night found a fair wind and reached Wakuma Bay in Shimotsumike District, Buzen Province. The sea of Saba is thought to be off present-day Hōfu in Yamaguchi Prefecture, and Wakuma Bay near Nakatsu in Ōita Prefecture. Of the eight, only the first has its author named; the author of this poem is not named.

First line, "kamojimono": "jimono" means like something: like a wild duck.
Second line, "ukine o sureba": "ukine" is sleeping afloat on the water, overlaying the duck with his own sleeping figure aboard ship.
Third line, "minanowata": the "mina" is a river snail whose innards are black; hence a pillow word for "kaguroshi" (jet-black).
Fourth line, "kaguroki kami ni": "ka" is a prefix: on my jet-black hair.
Fifth line, "tsuyu zo okinikeru": "zo" is a binding particle resolved by the attributive "keru" (kakarimusubi): the dew has settled, an exclamation of realization.
Source: Manyoshu
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