What does the 4-3 line pull indicate?

• A. Send me a slate.
• B. Stop and search where you are.
• C. Less air.
• D. Breathing on the EBS.

Answer: (C)

Underwater signaling relies on line-pull patterns to convey urgent status when talking isn’t practical. The 4-3 line pull is a specific rhythm used to tell the surface team that the diver’s air supply is running low. When this pattern is communicated, the surface crew knows to assess the gas situation, adjust work to conserve air, and plan an ascent or arrange for additional gas as needed. This makes the 4-3 signal the best fit for conveying limited air, because line-pull sequences are designed to deliver clear, rapid messages when visibility or noise makes verbal communication difficult. Other signals would represent different messages, not the low-air condition indicated by this pattern.