Which condition requires all vital sea suctions to be kept open?

Vital sea suctions are critical for maintaining the operation of various systems on a vessel, including firefighting, cooling, and bilge discharge systems. When the vessel is in a "Yoke condition," it represents a moderate state of readiness, where certain compartments may be closed to prevent the spread of smoke or flooding, while still allowing for vital operations. Keeping all vital sea suctions open during Yoke condition ensures that essential systems can operate efficiently in case of emergencies, such as fire or flooding.

In contrast, other conditions like X-ray or Zebra are more restrictive. X-ray usually pertains to a lesser security level where some compartments may be opened but still emphasizes control over potential flooding or smoke spread. Condition Zebra represents the highest state of readiness, where all watertight doors are closed and vital systems may be limited or isolated to enhance damage control, which could restrict certain sea suctions. Circle Yoke condition is an intermediate state that still emphasizes closing off certain areas but is less stringent than Zebra.

Thus, in Yoke condition, the priority is to maintain operational integrity while providing some level of protection, making it necessary to keep vital sea suctions available for use.