Tamim al-Dari asked Umar bin al-Khattab (may Allah be pleased with him) about travelling by sea, and he was a great trader by sea; so he ordered him to shorten the prayer, (and said): Allah Almighty says: "It is He who enables you to travel on land and sea." [Surah Yunus: 22]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5487