Sunday, November 30, 2008

How to find Mariner Licensing and Documentation Information Online

The primary website, has the majority of the information mariners need.
Here you will find the information mariners use when submitting applications for merchant mariner docu­ments. On the left side of this webpage, you will see the website menu bar, which provides a list of infor­mation topics that can be found on the site. In the middle of this webpage, you will see the pages most often accessed.­

At the bottom of each page on this website, you will see items to assist users, such as the NMC contact e-mail addresses, including for mariner application questions and the website e­mail address D05-DG­ for content issues, updates, and questions. You will also see the NMC help desk phone number: 888-427-­5662.

Homeport,, is the U.S. Coast Guard portal to information covering Coast Guard mis­sions. To access merchant mariner information, click on the "merchant mariners" button on the left-hand menu bar, approximately 10 buttons down from the top.

The difference between Homeport and the NMC website is that Homeport provides greater in­formation security. For this reason, mariners can use Homeport to check their application status online. It also provides access to the new sea service calculator, which will as­sist mariners in determining if they meet renewal sea service require­ments.

Coast Guard Listserve
The final Internet tool the NMC uses is the Coast Guard listserve, at grp_list.php. With this tool, they can notify the maritime community when there is new or updated con­tent posted on the NMC website. These notifications are sent via e-mail to subscribers.

How to Use the NMC Website
The NMC website contains information guides and checklists that provide guidance to mariners applying for a license or docu­ment renewals or up­grades.
PowerPoint presen­tations that walk mariners through the application submis­sion process,
all the forms needed to complete an appli­cation request.
It also provides information about MLD program poli­cies, links to other maritime sites, and a feedback page.
To navigate the site, just move your cursor over the left menu. As you move down the menu options, you will see sub-menu items or topics. As long as your cur­sor remains on the menu bar, the sub-menus will be viewable on the screen. To open these sub-menu items, move your cursor over and click on the topic you wish to review and that page will open.
The left-hand menu is organized by type of application, such as new mariner, renewal, or license, and required information, such as checklists for specific types of cre­dentials or user fees and drug test information.

Within the FAQ page you will find general information about what is required for the type of application being submitted. On the "new mariner" page, there is a help guide that will walk you through what is needed to ob­tain an MMD. Within the "merchant mariner info cen­ter" page, you will find policy and guidance, REC information, and course and examination information. The "application & forms" page has all the application forms you may need to apply for any of the various types of mariner licenses or documents.
There is even a pdf application form (CG-719B-F5) you can fill out online. The final pages you will find are "links/feedback" and "site map." Under "links/feed­back," you will find various links, such as the Trans­portation Worker Identification Credential (TWIC) site that provides you such information and the REC web pages that provide hours of operation, addresses, and phone numbers. The "feedback" section provides an avenue for comments, suggestions, and recommenda­tions. Under the "site map" page you will find a list of all the pages in the website. Each item is a link that will take you to that page when clicked.
Some upcoming website enhancements include pro­viding a keyword search function to quickly locate website information, and the ability to post large quan­tities of content in a format that eliminates the need to open multiple pdf and Word documents.

How to Use Homeport
Homeport provides mariners with a secure environ­ment to check on the status of an active application. Once on the Homeport homepage, find the "merchant mariners" button in the left-hand menu bar and click on that button. A new screen will open up and at the top of this new screen you will see" merchant mariner application status." When you click on it, another screen appears, and you will need to fill out all the re­quired fields.

Enter your mariner identification number (also known as reference number).
Enter your application number.
Or, if you do not know your identification number and application number:
Enter your last name.
Enter the last four numbers of your Social Se­curity number.
Enter your birth date.

Next, hit "go" and information on the status of your submitted application will be displayed. Remember Homeport is a security site, and part of its security measures is a time-out function. If the Homeport win­dow is open for more than 60 minutes, the system will "time out" on you, and you will have to log back in.
Note: You must access the merchant mariner ap­plication status tool though Internet Explorer. If you at­tempt to access Homeport from your AOL, Yahoo, or other Internet service provider accounts, the merchant mariner application function might not work.
The content of Homeport is organized slightly differ­ently than the NMC website, but most of the menu but­tons are the same. The first item on the menu is the merchant mariner application status. Next is the sea service renewal calculator, then "What's New at NMC." The content under this menu is the same as that of the NMC website.

How to Subscribe to the Listserve
Anyone can subscribe using the link grp_list.php. Once on the home­page, scroll down to "Mariner Licensing and Docu­mentation" and click. The NMC subject or topic-specific lists will appear. Select one you want to subscribe to and click the" subscribe" link. This will take you to the subscription page. Complete all the re­quired fields and click on the "subscribe" button. Re­peat this process for each list you want.

You will begin to receive all notices of new or updated information for that list. The notices provide you the name of the new or updated document, a brief de­scription, and a link that will take you to that content on the NMC website. The notice also provides a link back to the NMC CGLS lists and a method to unsubscribe to any of the lists.

If you want to be removed from a list, click on the link at the bottom of the notice, this will take you to the CGLS list page. Select the subject or topic you wish to "unsubscribe" and click the "unsubscribe" link. This will take you to the subscription page. At the bottom of this page, click the "unsubscribe or edit options" but­ton. This opens another page, and in the middle of the screen you will see an "unsubscribe" button.

This process generates an e-mail to you with a link you must click to complete the removal process. If you do not complete this step you will not be removed from the subscription list.

Lists include:

NMC updates: information about NMC's op­erations, ongoing process improvements, and important information about merchant mariner credentials.

NMC performance reports: information on credential production performance statistics,
including processing time, application inven­tory, and customer satisfaction.
MLD program policy updates: information concerning changes to regulations, Navigation and Vessel Inspection Circulars, and other pol­icy guidance.
REC news/announcements: concerning REC locations, hours of operation, contact informa­tion, and other operations information. Mariner information/news: information for mariners seeking licenses and/ or MMDs, in­cluding changes to credential application, physical and other forms, revisions to the checklist, information packets, instruction guides, information for healthcare profession­als, selected frequently asked questions, NMC points of contact, and other pertinent informa­tion.
Coast Guard-approved courses: information on Coast Guard-approved training, courses, examinations, course audits, and other infor­mation. Hope this will help you in finding information on licensing and documentation.

Sunday, November 23, 2008


Under a agreement between the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Coast Guard (USCG), software has been created to assist Volunteer Observing Ships (VOS) in submitting marine weather reports and participating in the Automated Mutual-assistance Vessel Rescue system (AMVER). This program allows ships to report marine weather to the National Weather Service (NWS) so that high seas forecasts will be as accurate as possible. The AMVER system allows ships to report their intended track so that in the event of an emergency all available resources may be focused on aiding ships in distress. Both of these systems are voluntary and are intended to aid all mariners on the high seas. All transmission costs are paid by the U.S. Coast Guard and NOAA. The ship is not responsible for any transmission costs, provided messages are sent to the address specified in the user's guide.

NOAA's SEAS (Shipboard Environmental data Acquisition System) program relies on volunteer observers to report weather at least four times per day at 00Z, 06Z, 12Z, and 18Z. Ships are encouraged to also submit reports at 03Z, 09Z, 15Z and 21Z. AMVER reports allow the U. S. Coast Guard to track a vessel's position. The AMVER program relies on ships to submit four types of reports: (1) Sail Plans; (2) Position Reports; (3) Arrival Reports and (4) Deviation Reports, when necessary. The U. S. Coast Guard updates their database with the position information from these reports, which allows them to identify vessels in the vicinity of a ship in distress.

Ships may participate in either the AMVER or SEAS program, but there are benefits to participating in both. A ship can reduce reporting requirements, since AMVER position reports are created from every weather message and automatically forwarded to the U.S. Coast Guard.
A typical voyage would require the submission of an AMVER Sail Plan before departure, submissions of weather reports four times per day and the submission of an Arrival Report upon arrival. A Deviation Report is only submitted if the ship deviates from its original plan. Ships that follow the same routes repeatedly get an additional benefit since Sail Plans can be stored in the system and recalled and modified rather than creating new ones.

The AMVER/SEAS PC software was developed for use with INMARSAT C transceivers. To participate in the AMVER/SEAS program the ship must possess an INMARSAT C transmitter with a floppy drive and the ability to send messages in binary format, and a 286 (or better) IBM compatible PC.
I have participated in this program and for the last 12 years, it one way to help the maritime industry. There is more information at the SEAS website at:

Saturday, November 22, 2008

Wednesday, November 19, 2008

Tuesday, November 18, 2008

Plotting RDF Fixes


Monday, November 17, 2008

Sunday, November 16, 2008

Saturday, November 15, 2008


WWV (Fort Collins, CO) 2.5, 5, 10, 15, 20 MHZ (AM)

8 Minutes past the hour

Atlantic highseas warnings

9 Minutes past the hour

Atlantic highseas warnings

10 Minutes past the hour

Pacific highseas warnings

WWVH (Hawaii) 2.5, 5, 10, 15 MHZ (AM)

48-51 Minutes past the hour

Pacific highseas warnings

The National Institute of Standards and Technology (NIST), broadcasts a time and frequency service from stations WWV in Fort Collins, CO and WWVH in Kauai, Hawaii., known to mariners as the "Time Tick", used as an aid in celestial navigation. Included in these are hourly voice broadcasts of current high seas storm warnings for the Atlantic, Pacific and Gulf of Mexico provided by the National Weather Service.The difference between the two stations is that WWV uses a male announcer for announcement of time, while WWVH uses a female announcer.
If you need more information on WWV, WWVH and time signals worldwide, look in NGA Publication 117 "Radio Navigational Aids"


Wednesday, November 12, 2008

Radio Direction Finder Fixes


Tuesday, November 11, 2008

Calibration Table Problems


Sunday, November 9, 2008

The Loran Navigation System

Line of Position from a Loran System
The name LORAN comes from the words LOng RAnge Navigation. The LORAN radionavigation system was originally designed in World War II as a navigation aid which could provide all weather fixing information for both ships and aircraft at sea. Its main use was in the Pacific theater to assist aircraft navigation in long overwater flights. The original system was known as LORAN A. It was used from 1955 through 1970 throughout the coastal waters of the North Atlantic and North Pacific regions. The last sta­tions remained operational until as recently as the late 1970's.

LORAN is a hyperbolic navigation system. In this hyperbolic system a master station generates a brief pulsed signal which is followed at a axed interval by a short pulsed signal, on the same frequency, from a slave or secondary station. The shipboard receiver, capable of measuring time in microsecond intervals, measures the interval between the arrival of the master signal and the slave signal. The resulting reading of time delay (TD) places the ship somewhere on a hyperbolic line, which represents a line of all possible points where the difference between the times of arrival of master and secondary signals is equal to the receiver reading. The loran lines printed on charts are hyperbolic lines. Each hyperbolic line is actually a line of position for the associated time differ­ence measurement.

A fix results when the receiver measures the time delays of two or more master/secondary combinations. The intersection of the hyperbolic lines representing the time delays measured is a LORAN fix. LORAN readings are considered most accurate when close to the baseline. The dashed lines extending from the base line outward from the master and secondary stations are known as the base line exten­sions. LORAN receiver readings of a station pair are not accurate if the ship is in the area of the base line extension. The typical LORAN C arrangement is for one master station to be grouped with two to four secondary stations (three secondaries is the typical arrangement). Such a grouping is called a chain. The secondaries of a given chain are designated X, Y, and Z. If four secondaries are in a chain, W is also included. Baseline distance between the master and secondary stations can be as much as 1000 miles.

Characteristics of the Loran C Navigation System
All LORAN stations in the system transmit their signals on a common frequency of 100 KHZ. The transmitted signal can travel by means of a sound wave (signal follows ground), or by means of the sky wave (signals reflected off the ionosphere). The ground wave range of LORAN C is about 1200 miles, and one hop sky wave range is about 2300 miles. One hop means one reflection of the transmitted signal off the ionosphere back to earth. The absolute maximum distance over which usable LORAN signals may be received is 3000 miles. A zone where no signal is received, called the shadow zone or skip zone, exists between the maximum range of the ground wave signal and the area where the one hop sky wave returns to the earth's surface. When in an area where only sky wave signals may be expected, sky wave corrections must be applied to the receiver time delay readings in order to correct them to equivalent ground wave values. These corrections (both day and night corrections) are printed on LORAN charts at the intersections of latitude and longitude lines.

The accuracy of positions based on LORAN C lines of position depends on the range of the receiver from the transmitting stations. At a distance of 200 miles from the stations accuracy within +/- 300 feet may be expected. At 1000 miles accuracy diminishes to +/- 500 to 1700 feet. Fixes based skywaves are substantially less accurate than ground wave fixes. As with any electronic navigation system, accuracy and reliability can be effected by interference. In addition, accuracy is decreased if the signal must travel a significant distance over land before reaching the receiver.

The format of the characteristic LORAN C signal is multi-pulse. Multi-pulse operation permits higher signal energy at the receiver while keeping transmitter power relatively low. As originally designed, the arrival of the signal from the master station triggered the signal from the slave.

The multi-pulse signal consists of 9 pulses for the master station and 8 pulses for each secondary, which are separated by 1000 microseconds. The ninth pulse, used to identify the master station, follows the eighth pulse by 2000 microseconds. The time interval between the transmission of master station signals and all secondary station signals is called the group repetition interval or GRI. This interval is unique to a particular LORAN C chain and is also called the LORAN C "rate". When expressing a LORAN C reading such as 797Q-X-1l340, the first four digits indicate the GRI, the letter represents the secondary station, and the last five digits represent the time difference reading in microseconds (millionths of a second).

The master station transmitter's ninth pulse is also used to send what is referred to as "blink." Blinking is used to warn receivers using the chain that there is an error in the transmission of a particular station or stations. An example is when the stations are not properly synchronized. Blinking is accomplished by alternately turning on and off the ninth pulse. The secondary station of the pair also blinks by turning the first two pulses of its group off and on. Blinking triggers an alarm in the shipboard receiver, so that the operator is warned against using the pair until blinking stops.

Loran C Receivers

Most modern LORAN C receivers provide displays of either actual time difference readings or direct latitude and longitude readout. When turned on the receiver should be automatically tracking all loran stations within range within about five minutes. If you are at the outer limits of LORAN C system automatic tracking may take longer. Most receivers have an alarm light that remains on until the receiver is tracking properly, and it will also come on whenever the receiver ceases to track a given station pair.

For the Coast Guard exam you should become familiar with plotting LORAN C fixes on charts with LORAN lines which are printed on the chart. It is also possible to plot LORAN LOP's on charts without a printed overlay by using the LORAN Lattice Tables. These tables are published by the Defense Mapping Agency and numbered in the 221-(XXXX) series. Plotting of LOP's by use of these tables is one of the problems which might be found on the license exam for deck licenses.

The Coast Guard will not have the actual lattice tables for your use during the exam. Instead, they have available a plotting sheet which incorporates the portions of the applicable lattice table necessary to solve the given problem.

Wednesday, November 5, 2008