江心补漏 (江心補漏) jiāng xīn bǔ lòu

jiāng xīn bǔ lòu set phrase to fix a leak in the middle of the river
Domain: Idiom 成语
Notes: Too late to be of use (Guoyu '江心補漏'; Mathews 1931 '江心補漏', p. 87)