End of evening nautical twilight (EENT)

Definition

End of Evening Nautical Twilight (EENT) is a military term used to describe the moment when the center of the sun sits 12 degrees below the horizon, during its setting phase. This term is significant in the military because it signifies the transition to night tactics and equipment in operations. In general, EENT marks the time when it becomes tough to distinguish the horizon at sea and the sky starts to appear completely dark.

Key Takeaways

1. End of Evening Nautical Twilight (EENT) refers to the precise moment when the center of the sun’s disc is 12 degrees below the horizon in the evening. At this time, the remaining light is barely enough for clearly distinguishing terrestrial objects.
2. In military operations, EENT is considered when planning field activities as low light conditions can affect visibility and thus tactical decisions. This period is often used to organize stealth operations or movements.
3. EENT can differ depending on geographical location and time of the year, hence, military personnel often carry nautical almanacs or utilise twilight calculators to determine the exact time for this twilight phase.

Importance

The term “End of Evening Nautical Twilight” (EENT) holds significant importance in military operations as it refers to the time when the sun is sufficiently below the horizon, such that tasks on surface of the sea can no longer be performed without the aid of artificial light.

This is crucial for military planning and operations because the visibility conditions drastically change during this period, usually indicating the transition from day to night operations.

Different rules of engagement and procedures go into effect during darkness, including considerations for night vision equipment, troop movements, stealth operations, and communication protocols.

Identifying the EENT helps military strategists to properly plan for these changes and ensure optimal operation efficiency and security during twilight and night-time hours.

Explanation

The End of Evening Nautical Twilight (EENT) is a term often used in military operations to denote a specific period of the day. This is a very important concept in military operations, as it establishes an optimal phase for conducting certain activities.

The terminology refers to the moment when the center of the sun’s disk is located just 12 degrees beneath the horizon, at which point natural light becomes insufficient for certain activities that require keen vision. This marks the transition from evening into full night, hence ‘the end of nautical twilight’. The primary purpose of assigning tasks to the EENT timeframe in military operations is to exploit the advantages of limited visibility conditions.

For instance, the low light condition following EENT is often used for executing covert operations or moving troops, given that reduced visibility potentially minimizes enemy detection. Additionally, any military activity like air strikes or ground operations that would benefit from this time can be scheduled accordingly.

It allows the military to maximize the operational advantages that come with the cover of darkness while considering the relative safety of their personnel and the successful execution of their strategies. In essence, the EENT is leveraged as a strategic tool to achieve tactical superiority in a potential conflict environment.

Examples of End of evening nautical twilight (EENT)

Operation Desert Storm (1991): During the Gulf War, the U.S. military extensively used EENT timings for planning missions and operations. The stealth aircraft and high-precision weaponry were deployed ensuring the advantage offered by reduced light conditions at the end of evening nautical twilight.

Battle of Al Faw (1986): During the Iran-Iraq War, the Iraqis launched a military operation to retake the Al Faw Peninsula from Iran. The operation commenced at EENT, taking advantage of decreased visibility to surprise the defending Iranian forces.

Normandy Invasion (1944): Recognized as the most significant operation of World War II, D-Day invasion also utilized the element of EENT. The first paratrooper drops occurred at night using the reduced visibility at EENT to help hide and obscure their movements, setting the stage for the beach landings at dawn.

FAQs about End of Evening Nautical Twilight (EENT)

What is End of Evening Nautical Twilight (EENT)?

End of Evening Nautical Twilight (EENT) is usually referred to the time when the centre of the sun is 12 degrees below the horizon and complete darkness has set in. It marks the end of nautical twilight. The EENT is frequently used in the military to end operations for the day.

What happens during the End of Evening Nautical Twilight?

At the EENT, the brightness of the sky makes it difficult to distinguish the horizon, making traditional navigation more challenging. In military contexts, operations often change or cease at EENT because the reduced light can make activities more dangerous or difficult.

How is EENT different from Civil Twilight?

Whilst Civil twilight ends when the center of the sun is 6 degrees below the horizon, EENT on the other hand takes place when the center of the sun is a further depth – 12 degrees below the horizon. As a result, EENT usually occurs later than Civil Twilight, when it’s darker.

Why is EENT significant in the military?

EENT is a major factor in scheduling military operations due to factors surrounding visibility. At this period of time, it usually becomes significantly harder to identify targets or navigate, signalling the transition from daylight activities to nighttime ones. This is particularly important for some military operations that require secrecy and cover of darkness.

Related Military Operation Terms

• VA Benefits: The advantages provided by the U.S. Department of Veterans Affairs to military veterans.
• Nautical Twilight: The phase directly before nighttime when the horizon becomes less clear and it’s harder to see due to lack of sunlight.
• Sunset to EENT: The period from the setting of the sun to the actual end of evening nautical twilight.
• Civil Twilight: The period after sunset or before sunrise when there is still measurable ambient light. Nautical twilight comes after civil twilight in the evening, and before it in the morning.
• Light Restriction Policies: Any restrictions or policies implemented by the military or VA regarding light usage during periods such as EENT.

Sources for More Information

Sure, here are four reliable sources where you can find out more information on the military term “End of Evening Nautical Twilight (EENT)”:

• U.S. Army Official Website
• U.S. Navy Official Website
• U.S. Marine Corps Official Website
• U.S. Air Force Official Website