This section provides comprehensive guidance on when and how to replace critical yacht components rather than repair them. You'll find detailed replacement timelines, cost-benefit analyses, and step-by-step procedures for commonly replaced parts including marine impellers, anodes, batteries, through-hull fittings, seacocks, propellers, and engine components. Each guide includes clear indicators that replacement is necessary, expected component lifespan by usage pattern, selection criteria for replacement parts, and installation procedures with safety considerations. The section helps yacht owners make informed decisions about repair versus replacement by comparing long-term costs, understanding manufacturer recommendations, and recognizing when a component has reached end-of-life. Special attention is given to parts that affect safety and reliability, with emphasis on proactive replacement before failure occurs. Whether you're planning routine replacements or responding to wear patterns, these guides ensure you select the right parts, understand proper installation requirements, and know when professional installation is mandatory versus when capable owners can handle the work themselves.