Musannaf Ibn Abi Shaybah

Hazrat Mughira says that I asked Ibrahim about praying in a boat, so he said that if one has the ability to pray outside the boat, then he should pray outside; otherwise, he should pray standing in the boat. If he cannot pray standing, then he should pray sitting. However, whenever the direction of the boat changes from the Qibla, he should also turn his own direction.