Tending lines are marked Red every 50 ft.

• A. Black or Yellow every 10 ft
• B. Red every 50 ft
• C. Blue every 20 ft
• D. Green every 100 ft

Answer: (B)

Distance marking on a tending line gives quick spatial awareness for the team. When the line is marked with red every 50 feet, it creates a clear, consistent rhythm that lets a diver or tend supervisor see at a glance how far the line has been paid out and how much remains to reach a target. This helps manage time, gas, and decompression considerations, and keeps the team coordinated even in low visibility or high-stress situations typical of EOD operations. In this context, red at 50-foot intervals is the standard pattern, which is why it is the correct description. Other color/interval schemes would provide different cues and aren’t the convention for tending lines in this scenario.