What is the visible horizon?

Master the Navigation, Seamanship, and Shiphandling (NSS) – Officer of the Deck (OOD) Phase 2 Exam with engaging flashcards and multiple choice questions, complete with hints and explanations. Prepare comprehensively for your test!

Multiple Choice

What is the visible horizon?

The visible horizon is the boundary between sea and sky as you actually see it, determined by how high your eye is above the water and how light bends in the atmosphere. On a ship, your height of eye gives you a horizon that lies farther away than if you were at sea level, and atmospheric refraction bends rays downward, letting you see a bit beyond the geometric tangent. So the horizon you perceive depends on both your eye height and refraction, not just the water surface itself. This is why the best description is the horizon from our perspective based on ship's height of eye and refraction. The other ideas describe idealized or different phenomena, not the real, sighted horizon.

The visible horizon is the boundary between sea and sky as you actually see it, determined by how high your eye is above the water and how light bends in the atmosphere. On a ship, your height of eye gives you a horizon that lies farther away than if you were at sea level, and atmospheric refraction bends rays downward, letting you see a bit beyond the geometric tangent. So the horizon you perceive depends on both your eye height and refraction, not just the water surface itself. This is why the best description is the horizon from our perspective based on ship's height of eye and refraction. The other ideas describe idealized or different phenomena, not the real, sighted horizon.

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