🔍 Key Concepts

• Effect of sustained wind on a rotary tidal current’s predicted set and drift • How wind from a given direction tends to push surface water (and thus current) in the same general direction it is blowing toward • Combining vector effects: comparing the predicted current vector with the likely wind-driven modification

💭 Think About

• Visualize (or sketch) the predicted current set (125° at 0.6 knot) as a vector, then think about how a strong northwesterly wind would alter that vector’s direction and speed. • Ask yourself: does a 22 mph northwesterly wind tend to increase or decrease the strength of the current, and does it tend to turn the set more toward or away from the wind direction? • Compare each choice to the original prediction—look for the one that shows a realistic change in both direction and speed due to a sustained wind.

✅ Before You Answer

• Convert the northwesterly wind direction into the direction TOWARD which the wind is blowing and relate that to the predicted current set of 125°. • Check which answer choices show a current that is plausibly stronger and shifted in a direction consistent with the wind’s push, rather than in an opposite or unrelated direction. • Verify that the new set and drift are not wildly different from the predicted 125° at 0.6 knot—rotary current predictions are modified by wind, not completely reversed.