What kind of dive can the standby diver perform once conditions are met?

The standby diver is typically positioned to provide immediate assistance and support in case of an emergency or issue during a dive. Once conditions are met, such as ensuring safety protocols are followed and assessing the surrounding environment, the standby diver can perform a no-decompression dive.

A no-decompression dive allows the diver to ascend without needing to make any mandatory decompression stops. This type of dive is suitable for ensuring a quick response while minimizing the risks associated with decompression sickness. It opens the possibility for the standby diver to quickly engage and assist in case of an emergency, as emergency situations often require immediate action.

The other types of dives mentioned—decompression dives, deep-diving operations, and tandem dives—present conditions or complexities that may not allow for the rapid execution and safety assurance needed in standby scenarios. A decompression dive, for instance, would involve stops during ascent to avoid decompression sickness, which would be impractical in an emergency situation.