Austronesian Sailing to the Northern Marianas, a Comment on Hung et Al. (2011)
Winter, Olaf, Clark, Geoffrey, Anderson, Atholl, Lindahl, Anders, Antiquity
As advocates of the out-of-Taiwan hypothesis of Remote Oceanic colonisation, Hung et al. (2011) want to claim the Marianas as the first beachhead of an early Austronesian dispersal from the northern Philippines (Figure 1). We argue that the proposition is neither supported by linguistic subgrouping or ceramic technology, nor by consideration of sailing conditions or historical voyages. These data together indicate that the origin of the Chamorro people of the Marianas was elsewhere in Island Southeast Asia (ISEA), and south of Luzon.
Given that it is practically impossible to drift 2300km from northern Luzon to the Marianas, Hung et al. (2011) credit their putative colonists with the ability to sail there. We argue that this passage was exceptionally difficult and that colonisation of the Marianas came more probably from a different direction. Sailing eastward from northern Luzon to the Marianas at 18[degrees] N must take account of a number of adverse factors: westward currents running at 0.9-1.8km/hr (Hydrographic Office 2005), an average of nine tropical cyclones, June to December, in the South China Sea (NGLA 2006), continual strong headwinds (NNE-SSE) that blow for more than 50 per cent of the time in any month (Table 1), and an absence of the persistent E1 Nino westerlies that facilitated eastward sailing in the South Pacific (Anderson et al. 2006). This is a daunting list and it may account for the absence in Riesenberg's (1965) data of any historical passages along this northern route by small craft. Neri's (1979) analysis of voyaging records from and near the Philippines going back to 1521 concluded that the few eastward passages were from the southern region. Even the Manila galleon to Acapulco, 1565-1815, found that the only feasible route eastward was first to sail north-east to latitudes around 35[degrees] N off Japan (Bankoff 2006).
Hung et al. (2011) do not disclose what kind of vessel they had in mind, but even if it were comparable to the modern Polynesian double canoe, the passage would still have been very difficult. Travelling about 185km per day and sailing up to 75[degrees] off the wind (Finney 2006), these canoes could advance directly windward at the rate of about 46km/day but, in the present case, they would lose most of that (22-44km) by adverse current drift. If it were possible to sail 185km directly towards the target on every day without headwinds (49 per cent of the days in the most favourable month, Table 1), the canoe would still have to travel at least 5000km (cf. Southampton to New York) to reach the Marianas. It is very doubtful, of course, whether sailing technology between 3000 and 3500 BP was at all comparable to that of the modern voyaging canoe. The outrigger and sail are attested in Malayo-Polynesian (not in Taiwan) by historical linguistics, but the fixed mast and standing rigging, critical to long-distance windward sailing, and the double canoe did not appear until much later (Pawley & Pawley 1994; Blust 1999; Anderson 2000). The effect of their absence is probably to be seen in the 3100 BP Lapita expansion, where eastward passages of 800km were possible, but only in the zone from north of New Guinea to as far east as Fiji, in which westerlies and northerlies blow with moderate frequency during the southern summer. There was almost no progress beyond the Lapita region into prevailing easterly headwinds for some 2000 years thereafter. It is most unlikely, therefore, that the technology required for "a remarkable feat of ocean crossing" Hung et al. (2011: 910) existed at the very beginning of Austronesian dispersal to propel the longest passage against prevailing winds in all Remote Oceanic prehistory, only to disappear before the Lapita era and then reemerge millennia later. Longer passages occurred in East Polynesia after about 1200 BP as in Marquesas to Hawai'i (3600km), and Rarotonga to New Zealand (2750km), but they were predominantly downwind in prevailing SE trade winds or subtropical easterlies. …