Navigation SystemsThe Ten most important steps for achieving a highly accurate fix for

a Private Aid to Navigation.

PART A

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Prepared by the Navigation Systems Staff of First Northern, USCG Auxiliary for the First District PATON - Private Aids to Navigation - Training Program.

Send your questions about the matter presented in the PowerPoint presentation to the DSO-NS for First Northern at

FrankJLarkin@verizon.net.

Minimizing Position Errors•Understanding the standard off station criteria.•Knowing that a buoy is not always on its specified position and what causes a buoy to move about.•Understanding the term, “Watch Circle.”•Understanding the affect of wind and current on position accuracy and how to minimize this error.•Knowing the effect that pre-underway set up checks and on-scene quality checks has on your credibility as an AV.

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More Position Errors

• Understanding the affect that the GPS’ antenna and the Echo Sounder’s transducer has on your accuracy.

• Knowing how to correct a depth to charted datum.• Knowing how to determine when an aid will be

stranded at low water.

Learning how to deal with all these factors is all part of today’s training

presentation.

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The Ten important Steps required to achieve highly accurate Fixes and Depths.

Step 1 – Review your Patrol Area Worksheet where a complete documentation check of each PATON’s Permit specification, the Light List narrative and the aid’s charted position, the symbols and abbreviation on the NOAA Chart has already been completed for you.

Step 2 – Perform a check of your GPS and Echo Sounder to insure that they are operating accurately before getting underway.

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Step 3 – Revuew the proper procedures for handling a hand-held GPS set with your crew. The specifics will be covered on a later slide.

Step 4 – Delegate responsibility for the various verification and checking tasks to members of your crew.

Step 5 – Perform the recommended techniques for maneuvering your vessel closest to each floating aid’s mooring.

Step 6 – Perform and record the all the required quality checks with your GPS and Echo Sounder while on scene at an aid. Update the Patrol Area Worksheet.

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Step 7 – Take and record the fix and depth on scene at the aid to Navigation Systems guidelines.

Step 8 – Evaluate the condition of each lateral aid per the IALA-B Aid to Navigation Standards. Record any observed errors on the Patrol Area Worksheet.

Step 9 – Evaluate the sequence of the aid’s position along the waterway for correctness. Indictate any errrors on the Patrol Area Worksheet.

Step 10 – Recheck all the data recorded on your Patrol Worksheet about each aid before leaving the scene.

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Step 1 – Compare your observations to the documentation information showing on your Patrol Area Worksheet.

Update the Patrol Area Worksheet and Accuracy Statement with the data collected on scene.The details of how this is accomplished will be shown during the Patrol Area Worksheet presentation.

The Good News is that this documentation analysis will be already completed for you on the Patrol Area Worksheet.

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Step 2 - Pre-Underway Set up Checks for your Measuring Equipment

Check that your GPS is set up correctly.Is WAAS enabled?Is the correct Lat/Long expression set up on your GPS?

[00-00-00.00 N / 000-00-00.00 W]

Does the Horizontal Datum on your GPS match the Horizontal Datum for the NOAA Chart that you are using?

–Use only NAD 83 or WGS 84 charts.

Is your GPS set to nautical miles? (New GPS sets come pre-set to Statute Miles.)

Is the correction for the transducer available?8

Step 2 - Pre-underway ChecksCompare the observed Lat/Long on your GPS for accuracy:

– Against a known location. (i.e. Your boat slip.)– Against another GPS. (Match antenna locations)– Against a charted fixed position. (A fixed aid or position)– Record how you performed this pre-check on your “Standard

Accuracy Statement.”

Check the accuracy of your echo sounder:– With a lead line or sounding pole.– With a hand-held echo sounder.– Record how you performed this pre-check on your “Standard

Accuracy Statement.” – Also record the Substation used.

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Be sure the GPS is operating in 3D – that is, viewing 4 or more satellites when a fix is taken.Be sure that the EPE reading is under 20 feet.Keep the hand-held GPS’ antenna facing upward.Don’t shut off your GPS between fixes.Don’t temporarily store the GPS set under objects or upside down in your pocket between uses, or, hold it upside down while standing around.Slow the boat down when taking a fix. Don’t race by the aid. Don’t move on until everything is checked.Verifying and checking aids should not a speed contest!

Step 3 – Know how to deal with a hand-held GPS.

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Step 4 – Delegate the responsibility for the various verification and checks tasks to members of the NS Team.

The most accurate and efficient fixes are taken in a NS Team environment, when . . .

You give each crew member a specific assignment. Every AV is aware of what is happening and is focused on

checking the accuracy of each reading. Each assigned AV is reporting their data to the AV recorder in

a pre-defined sequence. Time is provided for the AV recorder to receive and record

observations and to enter the data on the Patrol Area Worksheet without being rushed.

Recorded data is checked by another assigned AV. Input is printed, not scripted.

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Step 5 – Perform the suggested maneuvering techniques in order to get your

vessel the closest to an aid’s mooring.

Your goal is to get as close as possible to the a lateral floating aid’s mooring.

•Part B of this training describes a feasible approach for handling this problem, if you:

Take your fixes at times of high water.Keep your eyes on your echo sounder for

potential shoaling and obstruction problems.Have previously viewed the area at low water

and have noted any dangers or shoaling problems.12

Never put your vessel in any danger in order to get a fix or depth for an Aid

To Navigation.

CONTINUE THIS 10 STEP TRAINING IN PART B

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