Page 211 - Vol_2_Archaeology of Manila Galleon Seaport Trade

182 J. Kimura

10.5 Discussion

The underwater remote sensing survey and diving search have examined whether
either the shallow waters or the offshore water around a reef Mashione could be the
hazardous area which caused the wreck of the San Francisco, as depicted in the
historical records. The hypothetical location of the wreck is still considered to be in
the relatively shallow waters near coast, according to the description of the wreck
report. On the other hand, diving in the area has been extensive by Ama divers
gathering abalone, algae, and turban shell!sh from the rocky seabed, and during the
heyday of Ama !shing in the 1970s, more than four hundred Ama had been diving
in the waters concerned. No reliable reports have emerged about any !ndings of
artifacts, despite interviews with elder Ama divers as well as with village residents.
The marine geophysics survey has identi!ed anomalies in the shallow water areas.
The coastal currents and waves are high in the shallow waters and presumably
pushed wreck material into the sandy bottoms of the valleys, and this was con-
!rmed by the buried wreckage of the MV Rubens during an underwater metal
detector search. The sand sedimentation rate is relatively high at the bottom of the
valleys, and the fragments of the wreckage could be covered by the thick layer of
coarse sand.
Further underwater archaeological survey at the sandy areas and offshore around
the Mashione reef is needed, with the aim of !nding artifacts from the San
Francisco. All anomalies possibly related to the ferrous remains of the shipwreck
need to be assessed. To determine the contexts and extent of the site,
non-destructive underwater investigation by divers and remotely operated vehicles
will be conducted. The highest point of the reef is less than 14 m high, meaning it is
not entirely plausible to argue that the ship was heavily damaged by hitting the reef
—the draft of galleon’ shull was not deep enough. Hence further investigation is
needed for logical explanation of the site formation processes.

10.6 Conclusion

The Manila-Acapulco trade brought the Paci!c Ocean into a trade network, no
longer a frontier ocean, by linking seaports extensively along the Paci!c Rim
coasts. The sea lanes relying on powerful currents and seasonal winds sustained the
network between the most distant ports in Northern Hemisphere. The voyage in the
summer typhoon season, however, was extremely hazardous, in particular when
sailing northward up to the latitude of the Boso Peninsula. The loss of Spanish
galleons was considerable in the Manila-Acapulco trade. The incident of the San
Francisco in 1609 led to a new stage in the diplomatic relationship between the
rulers in Japan and Spain at the time, as examined by many historians. It was the
period when a new maritime policy related to the Manila galleon trade was