Something blocks your line of sight. On a road it could be hills, curves, etc.
during periods of restricted visibility
In open waters, visibility is generally considered restricted when it is less than 1 nautical mile (1.85 kilometers). This reduced visibility can be due to various factors such as fog, rain, or heavy seas. Navigational warnings and precautions are advised in such conditions to ensure safety at sea.
Restricted visibility refers to conditions where the ability to see and navigate is significantly impaired, often due to weather phenomena such as fog, heavy rain, snow, or smoke. In maritime and aviation contexts, this can affect safety and operations, requiring specific protocols and navigational aids to ensure safe travel. It is crucial for operators to be aware of visibility levels to mitigate risks associated with low visibility conditions.
Lights must be on during periods of restricted visibility
Lights must be on during periods of restricted visibility
In restricted visibility, a power-driven vessel underway is required to sound one prolonged blast every 2 minutes. This signal indicates the vessel's presence and helps prevent collisions when visibility is limited. The prolonged blast typically lasts about 4 to 6 seconds.
one prolonged blast
Navigation lights must be on during periods of restricted visibility.
lights must be on during periods of restricted visibility
A powerboat at anchor during periods of restricted visibility is required to sound a specific signal: it must make one short blast every minute. This signal helps to alert other vessels in the vicinity of its presence. Additionally, the boat should display appropriate anchor lights to enhance visibility.
A power-driven vessel underway in restricted visibility is required to sound a prolonged blast on its whistle every two minutes. This signal typically lasts for about four to six seconds. The purpose of this sound is to alert other vessels of its presence in conditions where visibility is limited, ensuring safety on the water.
Rules of the Road Rule 35 Sound Signals in Restricted Visibility/International (a) A power driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.