Yahya related to me from Malik from Safwan ibn Sulaym from Saidibn Salama of the Bani Azraq from al-Mughira ibn Abi Burda of thetribe of Bani Abd ad-Dar that he had heard Abu Hurayra speak about aman who came to the Messenger of Allah, may Allah bless him and granthim peace, and said, "Messenger of Allah! We travel by sea and we donot carry much fresh water with us so if we do wudu with it we gothirsty. Can we do wudu with seawater?" The Messenger of Allah, mayAllah bless him and grant him peace, replied, "lts water is pure, andits dead creatures are halal."
USC-MSA web (English) reference: Book 2, Hadith 12
Arabic reference: Book 2, Hadith 42