You are underway on course 120°T and can make 12 knots. The eye of the hurricane bears 150°T at 120 miles. The hurricane is on course 295°T at 20 knots. What course should you steer at 12 knots to have the maximum CPA?
Given: Own course = 120°T
Own speed = 12 knots
Hurricane bearing = 150°T
Hurricane course = 295°T
Hurricane speed = 20 knots
What is asked: Course to steer
Solution:
Given: Own course = 120°T
Own speed = 12 knots
Hurricane bearing = 150°T
Hurricane course = 295°T
Hurricane speed = 20 knots
What is asked: Course to steer
Solution:
- We are going to divide own speed by the storm speed.
- And then press inverse cosine.
- Answer in #2 shall be added or subtracted the storm course. (Rule: + if storm bears quarter, - if storm bears bow)
do you have storm avoidance problems asking distance?
ReplyDeleteMarCo,
DeleteYes I have and I just posted it a couple of minutes ago.
http://oic-nwreviewer.blogspot.com/#!/2014/03/storm-avoidance-maximum-distance.html
I encountered a problem w/ a given: Own speed=10knots, Hurricane Speed= 19knots, huricane bearing= 285°T... but the correct ans.was 226, (could u pls explain this) thank u
DeleteSir, your data is lacking. You don't give the ship's course. But anyway, I can guess where the storm is located in relation to your course because you have given me the answer which is 226° according to you.
DeleteSo this is it. 10 ÷ 19 = ans inv cosine = 58.24°. Since you said that the correct answer is 226°, so the storm is located to your bow; as 285° - 58.24 = 226.76°
I hope this answer your question. If you have other questions, share it here so that readers to this blog may contribute something.
Could you please explain further about this, (Rule: + if storm bears quarter, - if storm bears bow) Thanks.
ReplyDeleteIt simply means whether the storm is located to your front or to your back.
Delete