Abstract The article examines the question of why, despite a Maritime Labor Convention signed by almost all flag states and improved enforcement through regional port state control agreements, poor working conditions persist in the cargo shipping industry. To answer this question, this text analyzes the gaps in maritime labor law and its enforcement, the power resources of seafarers, and above all the market power of shipping lines. The concentration of capital and antitrust exemptions for shipping company alliances give shipping companies a strong position vis-à-vis crews, port operators, and states.