Sahih Muslim Book 20, Hadith Number 4700.

Chapter : The merit of joining a naval expedition for jihad.

It has been narrated on the authority of Umm Haram (and she was the aunt of Anas) who said: The Holy Prophet (may peace be upon him) came to us one day and had a nap in our house. When he woke up, he was laughing. I said: Messenger of Allah, what made you laugh? He said: I saw a people from my followers sailing on the surface of the sea (looking) like kings (sitting) on their thrones. I said: Pray to Allah that He may include me among them. He said: You will hip among them. He had a (second) hip, woke up and was laughing. I asked him (the reason for his laughter). He gave the same reply. I said: Pray to Allah that He may include me among them. He said: You are among the first ones. Anas said: ‘Ubada b. Samit married her. He joined a naval expedition and took her along with him. When she returned, a mule was brought for her. While mounting it she fell down, broke her neck (and died).