All Mainers are familiar with the VHF band used every day to communicate bridge to bridge.  VHF stands for "Very High Frequency" and covers the spectrum of radio wave frequencies from 30 MHz (megahertz) to 300 MHz .

"VHF" is common language to us all, but what does it really mean?

The frequency of a radio wave is the number of complete wavelengths that pass a given point in a second.  For example when you say that a wave has a frequency of 1-Hz you are saying that it has one cycle per second.  A megahertz designates a million cycles per second.  Within the VHF range, the wave is cycling between 30 million and 300 million cycles per second.

VHF waves, unlike longer waves, are not strongly reflected from the atmosphere; therefore, they do not bend readily around the Earth's curvature and cannot be transmitted beyond the horizon. Their range is further limited by their inability to pass through hills or large structures. Accordingly, VHF waves are limited to use in short-range, line-of-sight communications, including radio and television broadcasting, and in electronic navigation systems.

Like water waves, radio waves radiate away from a point of origin. When radio waves are generated, they spread out from the transmitting point in all directions at the speed of light-about 186,000 miles per second. When the waves encounter a receiving antenna, they cause electrons in the antenna to surge back and forth which are interpreted a data. 

Marine VHF radio refers to the radio frequency range between 156.0 through 162.025 MHz 

Typical marine use VHF channels and their frequency: 

The VHF band is not only used in marine radio communications.

Automatic Identification System (AIS)

AIS operates in the VHF band. The two frequencies used are 161.975 and 162.025 MHz. 

The AIS regularly  transmits every 2 to 10 second the vessel's: 

• MMSI number
• Navigation status, e.g. 'at anchor' or 'under way'
• Ground speed, from 0 to 102 kts in steps of 0,1 kt
• Rate of turn, 0 to 720 degrees per minute
• Position
• Heading and Course over Ground
• Time stamp

Also, every six minutes the AIS system transmitters :

• MMSI number
• Call sign
• Ship's name
• Type of vessel
• Dimensions of the ship
• Draft
• Destination
• Estimated time of arrival (ETA) at destination (captain's discretion)

Your AIS broadcasts all the information above while alternating between the two channels.

Limitations

VHF radio waves can only travel in a straight line which in practical terms, is the "line of sight" of those waves.   For example, the distance from my antenna to your antenna must be in a straight line if communications it to happen.  This is primarily caused by the curvature of the earth.

Other things which can adversely affect the transmission range od a VHF signal are:

• weather 
• land masses such as hills.  

This is often seen on the Tenn-Tom Waterway where AIS signals from other boats can fade in and out depending on how many hills are blocking the transmission.

To calculate how far a VHF signal can reach in statute miles,use this formula

distance in sm = 1.415 ∗ √height of antenna

In easy term, an AIS signal or a VHF radio call on a Higman Towboat with an antenna height of 38 ft. should equal:

1.415 * square root of 38 = 1.415 * 6.164

answer.....8.7 miles.....with no obstructions and good weather!

Attention:  All Wheelmen!

It is a Higman policy requirement for all Wheelmen to attend Advanced Pilothouse Management (Simulator) at least once every five years.   This is a three-day session held at the Seamen's Church at the Port of Houston.  Some of you have not met this requirement within the last five years and must do so as soon as possible.  

Steersman Taylor Milam with his training Captain, Michael Maneely.  Both men work on the M/V Higman Leader.

 See the dates below to choose when you will attend one of the five remaining sessions.  These dates are also listed in each Training Newsletter that is emailed to your vessel every other Wednesday morning throughout the year.  

Email Janis or Kelly in the Training Department to reserve your space for this training.  Or, you may call Janis at 281-864-6010 to make your reservation and arrange hotel accommodations.

2015 Advanced Pilothouse Management  (3- Day Simulator)

As the first quarter draws to an end we have already had over 1000 CBT Certificates issued. The 1000th Certificate issued was to Relief Captain Billy Coates on the M/V Colt Clary. For hitting the exact 1000th mark, Billy will receive a $150 Walmart gift card. Congratulations Billy!

Everyone keep up the work and you may be our next winner.

We are happy to announce Higman will be offering VOLUNTARY SUPPLEMENTAL LIFE INSURANCE from Guardian Life.

In the upcoming weeks you will receive a personalized packet in the mail from Guardian.  Each employee will have the opportunity to elect voluntary life insurance up to $200,000, guaranteed, with no medical questions to answer if you enroll during the initial enrollment period. The packet will give your monthly premium when you choose a policy amount of $50,000, $100,000 or $200,000. Most information has been populated for you, however, you will need to complete the form in its entirety, complete the beneficiary information, sign it and return it to Mary Kay Cole in the Channelview office by May 1, 2015.You can drop it off, email it, fax it or mail it.  Premium deductions will begin in June.

If you choose to decline coverage, please check the box that you do not want this coverage, sign and return to Mary Kay. If you decline coverage now, and decide at a later date to enroll, you will need to complete a medical questionnaire.

A quick and easy meal and full of flavor

Ingredients:

4 cups finely sliced cabbage (or 1 small bag of cole slaw mix)

1 chopped plum tomatoes

1/3 cup thinly sliced green onions

1/4 cup chopped fresh cilantro

2 tablespoons fresh lime juice

5 teaspoons olive oil, divided

1 pound tilapia filets or your fish of choice

1 teaspoon chili powder

8 corn tortillas

Directions:

Combine first 4 ingredients in a large bowl. Add juice, 1 tablespoon olive oil, 1/4 teaspoon salt and combine well.

Heat remaining olive oil in a large non-stick skillet over medium high heat. Sprinkle fish with chili powder and 1/4 teaspoon salt. Add fish to the pan and cook about 3 minutes on each side, or until fish flakes easily. Remove from heat and cut fish into bite size pieces.

Warn tortillas and spoon about 1/4 cup cabbage slaw down the center of each tortilla. Divide fish evenly among tortillas and serve with remaining cabbage slaw on the side.

Nutritional Information: 

Amount per serving (serving size: 2 tacos and 1/4 cup cabbage slaw).

Calories: 305

Fat: 9.8g

Carbohydrate: 30.1g 

Cholesterol: 75mg

Sodium: 445mg

Largest Riverboat ever built....Sprague

The SPRAGUE was the largest steam stern wheel towboat ever built for inland river service. The boat was launched in 1901 and went into service in 1902. She operated until March 5, 1948 when she was decommissioned at Memphis and from there first went to Baton Rouge, then to Vicksburg where she stayed permanently.