Which emergency line pull signal indicates immediate assistance is required without a response from topside?

The signal indicating that immediate assistance is required without a response from topside is represented by the 4-4-4 pattern. This signal is crucial for divers to convey an urgent need for help when they find themselves in a dire situation. By using this specific sequence, it communicates a clear and unmistakable message that the diver cannot manage the situation alone and requires prompt extraction from the water.

Understanding this signal is vital for ensuring the safety of divers, as it allows for swift action to be taken by the topside team. In contrast, the other signals are meant for different contexts, such as seeking assistance when the diver is capable of handling their issue (like the 3-3-3 signal) or indicating that no help is needed (the 1-1-1 signal). Thus, recognizing and responding to the 4-4-4 signal appropriately can significantly affect the outcome during emergencies in SCUBA diving situations.