91253-921-003 Water (6Mm) Seal - Overview. The 91253-921-003 Water (6Mm) Seal is an essential component in Honda marine engine systems. This 6mm water seal is specifically engineered to support the water sealing system in marine applications, preventing water from entering and ensuring optimal lubrication of critical engine parts. Designed to Honda's factory specifications, it guarantees seamless integration with existing engine parts, maintaining your marine engine's peak performance and durabi