Never fish in troubled waters.

不要浑水摸鱼。

You can fish in troubled waters.

你可以浑水摸鱼。

These are troubled waters indeed.

这些确实给地下水造成了麻烦。

He was fishing in troubled waters.

他在混水摸鱼。

Fish in troubled waters.

趁火打劫(混水摸鱼)。