What illumination level is required for water approaches extending to 100 feet from the pier?

The correct illumination level required for water approaches extending to 100 feet from the pier is established to ensure safety and visibility in potentially hazardous areas. A level of 0.5 foot-candle provides sufficient light for navigational purposes and enhances the safety of personnel and vessels in these environments.

This illumination standard is designed to mitigate risks such as slipping, tripping, or inadvertently falling into the water, particularly during low-light conditions. By ensuring at least this level of lighting, the risk of accidents decreases significantly, allowing for better visibility of potential hazards.

Other options represent higher illumination standards that may not be necessary for this specific application, as they could lead to overspending on lighting without significantly improving safety. For water approaches, maintaining the requirement at 0.5 foot-candle strikes a balance between adequate visibility and operational efficiency.