How can one determine the Qiblah direction while praying in a moving ship?
The Almighty has directed us to turn to the Qiblah while praying. Muslims always abide by this rule when they can. In situations where the Qiblah cannot be determined, they may face any direction they reasonably think the Qiblah lies. However, once a person has determined the direction and started praying, he will have fulfilled the obligation upon him. The Almighty does not burden the believers with unbearable responsibilities. There is a golden principle in the Islamic Shari'ah that none would be asked to do beyond what is humanly possible. This is why Muslim scholars say that one can keep on praying without giving attention to which way one happens to face in prayer while travelling in a ship.