When is a boat detail required?

A boat detail is typically required when dealing with larger water obstacles that present significant risks for personnel or equipment during parachute operations. The specified criteria for requiring a boat detail are designed to ensure the safety of jumpers in the event of a malfunction or for recovery efforts.

In this case, the correct choice relates to the depth and width of the water obstacle. When a water obstacle is more than 4 feet deep and 40 feet wide, this indicates a substantial area that could pose danger to jumpers. A depth of 4 feet is significant enough that, upon landing, jumpers may face difficulties in recovery or a higher risk of injury when attempting to maneuver or swim to safety. The width of 40 feet adds to the challenge of quick and efficient recovery, making it prudent to have a dedicated team available to assist.

The other options either set the thresholds too high or do not align with standard operational guidelines, which focus on the safety and efficiency concerning recovery in various water conditions. Recognizing the importance of depth and width, the criteria for needing a boat detail align with ensuring that sufficient safety measures are in place for jumpers entering potentially hazardous environments.