Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Drowning in clear water indicates drowning in abundant wealth or worldly affairs. Drowning in murky water indicates strife, heresy, and great worry. Surviving drowning is repentance, returning to God, and salvation from hardship.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Drowning indicates committing a great sin or falling into the hands of an unjust ruler. Whoever dies by drowning in a dream dies in a state of disbelief or heresy. Whoever sees himself drowning then surviving will reform his religion after its corruption.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Drowning is interpreted as ruin in religion or worldly life. Whoever sees a scholar drowning is drowning in his knowledge and heresy. Whoever sees himself helping a drowning person is helping someone in distress.