In the law of marine insurance, a warranty is one of the principal undertakings of the assured which has the role of determining the scope of the insurance contract. When breached, it provides the underwriter with a valuable defence regardless of the existence of a causal link between the breach and loss. A careful analysis of market practice reveals that breach of warranty defence is commonly invoked by marine insurers and consequently both the assured and insurer need to be aware of the law on this point. In view of the significance of the concept of warranties, it is somewhat surprising to find that at present no study has offered any substantial treatment of this aspect of law. This book is designed to fill this gap by providing a comprehensive and critical approach to marine warranties. The primary purpose of the book is to review the law in respect of marine insurance warranties and identify existing and potential difficulties in this area. The book is divided into three main parts. Part 1 evaluates the current law, highlighting the potential problems and offering some solutions. In Part 2, the interrelation between breach of warranty defence and other defences afforded to the insurers is examined. In the final part, the possibility of reform in this area is discussed in the light of a comparative study and recent developments in the marine insurance. The book constitutes an important addition to the bookshelves of practitioners, academics and students in need of an authoritative and comprehensive guide to this area of expertise.