The divers are of many nationalities, principally Japanese and Malays, and the former are said to be the most efficient. Previous to 1890, they were mostly whites, and were paid at the rate of £40 per ton of shells; but increased competition and the influx of cheaper labor caused a considerable decrease in the rate of compensation, driving most of the white men out of the employment. At present the Japanese almost monopolize the business. Of the 367 divers licensed at Thursday Island in 1905, 291 were Japanese, 32 were Filipinos, 21 were from Rotuma Island, 16 were Malays, and 7 were of other nationalities; this shows how completely the white man has been driven out of this skilled, branch of labor.
The oysters are so scattered that considerable walking is necessary to find them. They usually lie with the shells partly open, and in grasping them the fisherman must be careful not to insert a finger within the open shell, or a very bad pinch will result. The progress of the vessel must be adapted to that of the diver, and when a good clump of oysters is found it may even be desirable to anchor. If the current and wind are just right, the vessel may repeatedly drift over a bed, the diver ascending and remaining on board while the vessel is retracing its course to the windward side of the reef. On new grounds, the nature of the bottom is determined by casting the lead properly tipped with soap or tallow, and the prospects for oysters thus determined without descending.
During good weather and in eight or ten fathoms of water, a diver can work almost continually, and need not return to the surface for two hours or more; but as the depth increases, the length of time he may remain at the bottom in safety decreases almost in geometric ratio, and he comes to the surface frequently for a “blow” with helmet removed. Evidence secured by a departmental commission of the Queensland government in 1897, showed that in good weather at a depth of eight or ten fathoms, a diver works from sunrise to sunset, coming to the surface only a few times. In a depth of over fifteen fathoms the attendant usually has instructions not to let him remain longer than fifteen minutes at a time; yet a diver’s eagerness in working where good shell is plentiful sometimes impels him to order the attendant to disregard this rule. The very great pressure of the water amounting to thirty-nine pounds or more to the square inch is liable to cause paralysis, and death occasionally results. In working at a depth of twenty to twenty-five fathoms, a diver is rarely under water longer than half an hour altogether during the day. The greatest depth from which shell is brought appears from the same evidence to be “30 fathoms and a little over”; but at that depth where the pressure is seventy-eight pounds to the square inch the fisherman remains down only a few minutes at a stretch, and should be exceedingly careful. The work is injurious, and even under the best conditions the diver not infrequently becomes semi-paralyzed and disqualified in a few years. Notwithstanding that the work is performed by men in vigorous health, nearly every year there are from ten to twenty-five deaths in the Queensland fleet alone; three fourths of these are due to paralysis, and most of the remaining result from suffocation, owing largely to inexperience in use of gear. From five to ten years is the usual length of a man’s diving career, although in the fleet may be found men who have been diving for twenty-five years or more.
George Frederick Kunz and Charles Hugh Stevenson, The Book of the Pearl: The History, Art, Science and Industry of the Queen of Gems (1908), chapter nine, ‘Pearl fisheries of the South Sea Islands’