Abu Hurairah (RA) said: “A man asked the prophet (peace be upon him): ‘O
Messenger of Allah (peace be upon him), we travel by sea and we take a
little water with us, but if we use it for Wudu’, we will go thirsty.
Can we perform Wudu’ with seawater?’ The Messenger of Allah (peace be
upon him) said: ‘Its water is a means of purification and its dead meat
is permissible.'”
(Sunan an-Nasa’i, Vol. 1, Book 2, Hadith 8)