You are underway on course 172° T at 18.5...

Question 1 of 2707066636eea28f7522a1c51b72d

You are underway on course 172° T at 18.5 knots. The current is 078° T at 2.8 knots. What is the speed being made good?

Question 1 of 27070

You are underway on course 172° T at 18.5 knots. The current is 078° T at 2.8 knots. What is the speed being made good?

🔍 Key Concepts

• Use the current triangle / vector triangle to combine ship’s speed and current • Recall that speed made good is the magnitude of the resultant vector of your ship’s motion through the water and the current • Break each vector into north-south and east-west components using basic trigonometry (sine and cosine)

💭 Think About

• Is the current generally helping you (more or less in the same direction you’re going) or opposing you? That tells you if speed made good should be greater or less than 18.5 knots. • When you resolve the ship’s motion and current into components, what do the north-south components do to each other (add or subtract)? • After you find the resultant north and east components, how do you recombine them to find the resultant speed (Pythagorean theorem)?

✅ Before You Answer

• Be sure you are using true bearings correctly: measure all angles from true north, clockwise. • Double‑check that you use correct signs (north vs south, east vs west) when resolving components so you don’t accidentally add when you should subtract. • After your calculation, ask: is the answer reasonable given the direction of the current (should it speed you up a little, slow you down, or mostly push you sideways?) and is it close to one of the choices?