油舱清底 tank stripping

清底半径 radius of clean-up at floor

摸清底细 Ascertain The Actual Situation

海底清洁工 Seabed Cleaner

彻底清扫 clean up ; Thorough cleaning

彻底清洁 thorough cleansing ; thorough clean ; give a thorough cleaning ; a thorough cleaning

井底清洗 bottom-hole cleaning ; hole cleaning

彻底调查清楚 check up on ; investigate thoroughly ; make a thorough investigation