What indicates that the crew life vests are ready for use?

The indicator that crew life vests are ready for use is that they are present and not tampered with. This means that the vests should be stored in their designated locations and should appear intact and secure, ensuring that they are available for immediate use in case of an emergency. Proper storage without signs of tampering assures the crew that the equipment has not been altered or compromised, allowing for reliable usage when necessary.

Other conditions that might indicate issues, such as being stored in an unsealed condition, missing from their storage, or exposed to moisture, would suggest that the life vests could be damaged, ineffective, or unavailable when needed, thus compromising safety during an emergency scenario.