Through the age of sail Japanese sea drifters involuntarily crossed the Pacific. The sengokubune ship which tended to lose its rudder in storms and drift nearly endlessly. Several made it to North America (see The Shogun's Reluctant Ambassadors by Katherine Plummer), as did at least one Manila Galleon whose entire crew had expired. According to Sandy Lydon's Chinese Gold, the Pacific's clockwise current is known as Kuroshiro, black tide, in Japanese; and as Wei-Lu, ultimate drain, in Chinese.
On April 20th 1774, near Carmel, California, Juan Bautista de Anza wrote in his diary about seeing part of a wrecked ship of unknown origin (his compatriot Garcés did not record it). Here is his complete diary entry and the translation given by Web de Anza:
Dia 20 Miercoles. Pasé a la Mision de San Carmelo, distante del Presidio poco mas de legua tanto por ver este nuevo establecimiento, y ultimo de la California septentrional; como por pagar la visita, que ayer me hizo al Reverendo Padre Superior de los Misioneros de ellos. Pocos dias antes de mi arrivo aqui, se varo en la Playa que hai inmediatamente un Palo de Barco, no conocida su construccion por los nuestros, que aqui abitan ni su madera, el qual se persuaden se quebró al segundo tercio; este todo pasado con clavos mui fuertes de una Cabeza larga, y dos puntas, que no pasan a remache, cuio fierro nada se ha enmojecido, ni las puntas que quedarón, donde se quebró estan embotadas, por cuias dos ultimas circunstancias infieren los tales quales Peritos, que hai aqui en el asunto de Embarcasiones, que no ha mucho tiempo se desgracio la de adonde era esta Pieza, que en primera ocasion que se proporcione, para el Puerto de San Blas se conducira para que sea exactamente examinada.
Wednesday, April 20. I went to the mission of San (Carlos del) Carmelo, distance from the presidio a little more than a league, both to see this new establishment, the last in northern California, and to return the visit made me yesterday by the reverend father superior of its missionaries. A few days before my arrival here the mast of a ship was stranded on the nearby beach, whose construction and the wood of which it is made are unknown to those of our people who live here, but they believe it was broken two-thirds off. It is entirely run through with very strong nails with long heads, and with two points which do not pass through to be clinched. Their iron has not rusted at all nor are the points blunt which projected where it was broken. From these last two circumstances the few persons who are experienced in the matter of vessels infer that it cannot be very long ago that the vessel from which this mast came was wrecked. At the first opportunity that offers it will be taken to the port of San Blas in order that it may be carefully examined.
So clearly the metalwork was different from what he had seen in the past. The nails were of higher quality than those he knew in Mexico. Did Japanese ships make masts using two-pointed iron nails, or is another origin more likely?