Abdullah bin Amr bin al-As (may Allah be pleased with them both) says: The Messenger of Allah (peace and blessings be upon him) said: "For one who has not performed Hajj, a Hajj is better than ten military expeditions; for one who has performed Hajj, a military expedition is better than ten Hajj pilgrimages; an expedition at sea is ten times better than an expedition on land; whoever crosses the sea, it is as though he has crossed all the valleys; and the one who becomes seasick in it (the sea) is like one weltering in his own blood."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 8667