Which weather element cannot be measured...

Question 1 of 2921866636ee928f7522a1c51a6ac

Which weather element cannot be measured accurately while on board a moving vessel?

Question 1 of 29218

Which weather element cannot be measured accurately while on board a moving vessel?

🔍 Key Concepts

• Relative vs absolute motion of the ship compared to the environment • How common shipboard instruments (thermometers, barometers, hygrometers, wave sensors) take their readings • Which weather elements depend on the vessel’s speed and motion for their apparent value

💭 Think About

• Think about which of these elements is measured from inside a sheltered part of the ship and which one relies on the sea surface motion relative to the vessel. • Ask yourself: if the ship speeds up, slows down, or changes course, which of these readings would be most affected even though the real environmental condition has not changed? • Consider which elements can be measured in the ship’s own air space (like an instrument screen), versus which one requires observing something outside the ship that is also moving.

✅ Before You Answer

• Identify which elements (A–C) are normally measured in a screened, protected location on board and therefore are largely independent of ship speed. • For each choice, imagine taking repeated measurements at different ship speeds in identical weather—would the true value change, or just your observation? • Focus on which option depends on a time interval between repeating events observed on the sea surface, and how the ship’s forward motion might distort that timing.