Not celestial navigation...but

[Roger (Ninette Manitoba)]

Stu, I think one of the important points

of this exercise is that language used can be misleading and that we have to have an open mind to a few different solutions to the problem, and certainly different techniques for getting to those solutions.When we are at sea, and data comes to us that is potentially confusing, we have to ensure that we question the data, review the problem, and think of alternate reasons for the data being presented as it is. Similarly when we come to a solution that does not seem to make sense, we have to review both the problem, the techniques we used to get to the solution, and perhaps reinterpret what the original issue was.I think nothing points that out better than the assumption (by some) in the current problem that a convergance was in the future.

 

[Ross]

Roger, all that you say is valid. We did encounter

a problem here that could result in a disaster at sea. There was some ambiguity in the statement of the problem. There was a delay in the response to the questions. Here it was all just fun and there was no harm. Prior to the electronic age all sightings were relative to the ship. On small boats if someone is on radar watch and reports a contact I feel that it should be relative to the ship not magnetic or true. You would be greatly handicapped if someone said "watch out for that car coming from the east!" instead of saying "watch for that car on your left!"

 

[Stu Jackson]

Roger, I agree

and that's one of the reasons that I suggested specificity - but that's just my engineer-in-me speaking. What we've learned here is that there are a number of different ways of doing things, but that one needs to be chosen and adhered to on any given vessel or all heck can break loose.Ross' points are also valid, just make sure you're driving south with that kinda input! Only one thing I'd like to know: what does magnetic or true have anything whatsoever to do with this original question or it's proper answer? (other than the difference between relative and true related to bearings)

 

[Roger (Ninette Manitoba)]

and even then there can be errors

How many times have you directed someone to the left, and as they started to take action, you said, No, I meant the other left, sorry!Similarly, a number of years ago, we were using GPS to find an old WWII crash site. One of the data points for our current position was easily 10 miles north of our current location and 'not in sync' with the other multitude of data points. We quickly discarded that position data as an error. Even high tech data fails occasionally, beer cans get left near the compass, we get dyslexic with numbers, or misinterpret information.I think this is why we should be doing these exercises in the first place; not so much to succeed each and every time, but to determine how where and why we are making errors.Carry on! Next problem please someone.

 

[Ross]

In flying airplanes the crew will report other

aircraft with a clock reference with the nose of their airplane at noon. So they might say "6 single engine fighters at 3 o'clock, high, in coming.I like these exercizes and hope that we can continue them. I would ask just one thing, Please don't edit the original post without clearly stating the changes that are made.Now on to the next.

 

[Ross]

very nicely done.

Time for the next one.

 

[Stu Jackson]

Thanks, Donalex, that is

what Dutton's defines as "The Geographic Plot" as compared to a relative plot or a radar plot (which also is different than a relative Maneuvering Board Plot).It's what most people who use charts (us "ancients") would expect to use to visualize the issue.Well done and much appreciated.