Sight Reduction Bowditch II

Mariners, I am about to sit for a celnav exam and am requesting any advice on specific pages which offer a solid template of examples to refer if any brain farts occur for the full sight reduction process in all pubs, but specifically H.O. 229 and Bowditch II which are provided in the exam room. I am specifically concerned with a LOP derived from a cel body. Thank you in advance.

My Advice:
Try and find a copy for yourself and study it at home (or work) before you take the test. Get used to referencing Bowditch as you work through your practice problems. Learn both the calculator method and interpolation, the understanding of how the math works will help you keep from making mistakes. Get a good calculator, I recommend a TI36x.

The books on the testing center are best when you are really familiar with them. Yeah, I could tell you to reference equation 4(a) on page 504 (I think) but unless you’ve practiced it that way, it won’t help.

If your not already using lapware and going through the solutions, you should give it a try. It breaks every problem down pretty well, although maybe a little lacking if you’re a calculator man like myself.

Good luck!

My Advice:

Repetition, Repetition, Repetition.
Lapware, Lapware, Lapware.
Lather, Rinse, Repeat.

Don’t blow off minor adjustments like temperature and humidity, or index error, and make sure you are looking in the right column for a star or a planet. They like to throw you these curve-balls during the exam, hoping you’ll fall for it, and have incorrect answers to choose from in case you fall into the trap.

When you finish, go back and do every single problem all over again, COMPLETELY. I’m glad I did, I found I accidentally wandered into an adjacent column on my double-check, and it made the difference of pass or fail.

Do the questions you know you got down solid first. then tackle the time consumers last.

Take your time, take a few relaxation breaths.

Good Luck!

Mariners, thank you for the info. I have been at it with Lapware for a good two months. Just getting the last minute jitters before I test.

Practice your Azimuths for gyro error and your sight reduction for LOP using the format shown on the inside front pages of any Pub 229s. That way you’ll essentially have your notes with you.

I noticed you are an Aussie? I wonder how different you exam is from the USA. Anyhow, I don’t know what particular problems are tripping you up, but on the USCG exam, probably the most involved problem is a 3-star running fix taken over a period of time. My experience and observation has shown the most common trip-up on the LOPs is not advancing (or retarding) them correctly. If the answer they want is at the exact time of a particular star sighting, I draw that first in RED pencil. Then I KNOW I am somewhere along that line. Then I pick the LOP that is most perpendicular to the LOP, very lightly pencil it in, then advance (or retard) that LOP, and I actually use a RED pencil so I don’t get confused. This should get you in the ball park. Do the third LOP and advance in RED for further confimation

I always deduce my 3 sightings in 3 columns on my scratch paper. on the left gutter of the paper I list all the steps. LHA, GHA, increments, etc. and dedicate each line on the page to that adjustment. There are a couple examples in the front of H.O. 229 or Nautical Almanac (in the examples they do it left to right) if your brain vapor-locks.

Lapware is helpful when you see their solutions. The solutions are color-coded so you can see what numbers are given in the problem, what is found in your tables, and what is calculated. This helps immensely.

I do all my calculations laid out the same way on my paper every time. So sometimes I can immediately see if I accidentally skip a step. this is why I say repetition, repetition, repetition. I had alot of the steps PAINSTAKINGLY MEMORIZED. Some I had the luck of knowing where the examples were, mostly H.O. 229 and the NA. I even went as far as making “cue cards” for each problem written on a 3x5 inch card, just to jog my memory while I listed all the steps on the left side of my paper.

Honestly I was a bonehead at this stuff, but I went over it again and again until it almost killed me, but it made me stronger.

Hope I helped a little, I dont have my books or notes with me at the moment, but If you ask something more specific, we can probably help you out.

We feel your pain.

Stellarseas, thanks for the information. Contrary to my location in Australia I am an American. My wife is the Aussie. I am about to fly back to the States to sit this exam and posed the question to see if anyone has any tips I may be overlooking, I don’t want to have to risk any f-ups. I laughed to myself when you mentioned the three star fix, your right, it was exactly what made me panic a bit after not going over one for a while. I have been doing basically everything you mentioned less the cue cards. However, I have been making myself personal examples of all the types of problems for study references and they have been critical for a quick review. Like you and the others said, I think it is just the grueling process of repetition.

I passed the oceans exam and the license is in the mail. Thanks for the help mariners! Next stop, job search.

Congratulations, Marine. Having the Oceans endorsement should help you stand out from the other applicants.

Good luck with the job search.