سنن ابن ماجه

It was narrated that Sulaim bin ‘Amr said: I heard Abu Umamah saying: I heard the Messenger of Allah (ﷺ) say: “The martyr at sea is like two martyrs on land, and the one who suffers seasickness is like one who gets drenched in his own blood on land. The time spent between one wave and the next is like a lifetime spent in obedience to Allah. Allah has appointed the Angel of Death to seize souls, except for the martyr at sea, for Allah Himself seizes their souls. He forgives the martyrs on land for all sins except debt, but (He forgives) the martyr at sea all his sins and his debt.”