水底撈針 [－－捞针]

Jyutping seoi2 dai2 laau4 zam1
Pinyin shuǐ dǐ lāo zhēn

Definitions (Wiktionary)
  1. phrase, idiomatic
    Synonym of 大海撈針／大海捞针 (dàhǎilāozhēn).
    (syn.) 大海撈針, 大海捞针