need help my brain is toast

MrA said:

Problem solved! Thanks to the crew of Sailnet.....getting ready for ASA 105 written test and for the life of me I can't figure these two problems out? any step by step solution would be greatly appreciated. Your are on a compass course of 300 degrees when you note the monument and the lookout tower on Cuttyhunk Island are in line. Using s Pelorus you determine that the transit formed by the monument and the tower is 130 degrees to starboard. What is the deviation of your compass for this heading?....and the second question is a compass course of 317 degrees and a pelorus transit of 064 degrees to starboard again solving for deviation. I'm too old to be school material, in my youth I was a math wiz but now too many brains cell have retired on me when I need them the most. I just don't understand the process to solve these questions thanks augie

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Transits for compass error.

The simplest way to use a transit to figure out the compass error is to steer directly on the transit.
Not always convenient.

The true bearing of the transit can be read by line the parallel rules or plotter. with the two objects in transit. And move to the rose.

Read the variation from rose apply annual change (unless question tells you to ignore it)

True bearing of transit
Variation from chart rose
Magnetic bearing

Deviation.

Compass heading.

This deviation is just for the course in question. To get the deviation on an other course you need a compass you can take an azimuth with or a pylorus.

In this question you are using a pylorus.

Zero is usually right ahead and measure Port, (Red) or Starboard(green) from right ahead.

Steering 300. compass
130 to starboard or right o the heading. Add
430 compass
- 360
070 is the "compass" bearing or azimuth of the transit it if it had been taken by your boats steering compass

Compare this to the transit as taken from the chart.

The second bearing is from a heading of 317 compass
067 to starboard or right of the heading
387 compass
360
027 is the compass bearing or azimuth of the transit if it had been taken with your boats steering compass

This question can only be answered by taking the true transit and variation from the chart or having been told what they are as part of the question.