This paper deals with the pricing differences between a mutual co-operative underwriting system and a fixed-premium underwriting system in providing coverage for marine liability. There has been much debate in recent years within the marine liability underwriting industry over which method fosters more competition, and hence, lower premiums for shipowners who are required to carry such coverage in order to operate. This paper will look at the current mutual marine insurance industry (Protection & Indemnity Associations or P&I Clubs) to compare its pricing both before and after the entry into the market of the fixed-premium underwriters, using data from 1985-2000 that encompasses both a major loss cycle and normal cyclical pricing variations. This analysis will hopefully provide information on whether mutual premium levels for the P&I Clubs differed substantially with the entry of the fixed-price competitors. This is important for the individual shipowners belonging to these mutual underwriting associations, because any variation in premium pricing could mean the potential for either great savings or tremendous losses. / Master of Arts