我國舊海商法第115條規定：「為救助或意圖救助海上人命、財產或因其他正當理由變更航程者，不得認為違反運送契約，其因而發生毀損或滅失時，船舶所有人或運送人不負賠償責任。但變更航程之目的，為裝卸貨物或乘客者，不在此限。」現行海商法係於西元1999年修正，前開條文經修正為第71條，規定：「為救助或意圖救助海上人命、財產，或因其他正當理由偏航者，不得認為違反運送契約，其因而發生毀損或滅失時，船舶所有人或運送人不負賠償責任。」我國學術論著中，甚少就偏航加以討論。因此如何定義偏航、偏航是否合理、其法律效果為何，實有探究之必要。本文即就海事法中偏航之定義、合理偏航之判斷標準、非合理偏航後之法律效果等，參酌英美法院之相關案例及國際公約加以討論，期使偏航之內涵與法律效果得以明確之呈現。

The revised Article 71 of Maritime Act stipulated as follows: ”Any deviation in saving or attempting to save life or property at sea or for other reasonable cause shall not be deemed to be an infringement of the contract of carriage, and neither the carrier nor shipowner shall be liable for the damage or loss resulting therefrom”. The unreasonable deviation is breach of contract of affreightment. The article is starting from the basic concept of the deviation, and introduces briefly the legal questions about deviation of the ship, the essential factors of the deviation, the standards for testing the reasonable or unreasonable deviation, the causation of the loss of property and the act of deviation, the legal liability for unreasonable deviation.