With regard to mining technology, it was reported that two bathymetric surveys had been conducted during the reporting year to identify a suitable flat area about 500 metres deep to carry out the operational test of the underwater crawler.
关于采矿技术，据报报告所述年份内已进行了两次测深勘查，鉴定约500米深的适当平坦地区以进行水下履带式牵引装置操作试验。