VHF marine radios are essential equipment on a boat. The usable range of a VHF radio system is dependant on several factors including the weather, the boat , the antenna and the health of the radio.

The most important part of the system is the antenna. Marine antennas should be mounted as high as practical. Another important quality of an antenna is it's gain.

Gain is rated in decibels or dB. Most experts recommend a quality antenna with a gain of 6 dB for powerboats under 50 ft. The antenna system can be tested by measuring the VSWR of the antenna. The VSWR should be as low as possible, typically 1.5 to 1 or lower on a healthy antenna.

"I have a high regard for the Coast Guard because I'm aware of what they do...and the risks that they take...if you don't have times to get off a 'Mayday', then Rescue 21 is helpful for people that use the water for pleasure and for commercial use. Probably the greatest asset the Coast Guard has had as a benefit for their use is Rescue 21...the equipment saved my life." Boater George Strawn - describing his rescue off Ocean City Inlet in Maryland. (December 2005)

For recreational and professional mariners, safety is a top priority. However, safety sometimes may not be at the top of the list. Whether it is commercial or leisure fishing, chartering a vessel, working on a freighter or just enjoying a sunny day on a boat, people just want to do their own thing and get lost in whatever task is at hand. Unfortunately, disaster can strike at any time. Harsh weather, vessel malfunctions or a person accidentally falling off a boat can mean tragedy if not dealt with quickly. Mariners may not have time to grab life jackets, let alone trying to call for help. For these and other reasons, the Coast Guard modernized outdated National Distress and Response System and created Rescue 21. The goal - to minimize the time between a call for help and the rescue.

Rescue 21 provides direction-finding capability and Digital Selective Calling, resulting in a more timely response to mariners in distress. The system also allows for protected communications during law enforcement and homeland security operations. Digital Selective Calling uses digital data rather than voice transmission to increase the range of maritime communications, the accuracy of data transmitted and the ability to direct that information to selective units.

"Rescue 21 is a leading edge VHF-FM radio system that replaces the outdated system from the 1970's," said Chief Petty Officer Mike Smith, an operations unit controller in the Puget Sound Joint Harbor Operations Center at Coast Guard Sector Seattle. "Rescue 21, how it applies here in the Puget Sound area is that it gives the ability for the Coast Guard to monitor simultaneously different radio frequencies and direction find on those frequencies and provide assistance to the mariners out on the water."

Rescue 21 replaces outdated technology and provides the Coast Guard with upgraded tools to protect the nation's coasts and rescue mariners at sea. Currently, Rescue 21 is operating across 16,557 miles of coastline. When completed, the system will cover more than 95,000 miles of coastline, navigable rivers and waterways in the continental United States, Alaska, Hawaii, Guam and Puerto Rico.

As of July of 2008, Rescue 21 has been fully implemented in the 13th District.

"Rescue 21 is a series of remote towers that are capable of transmitting, receiving and direction finding," said Eric Cookson, an operations unit controller in the Puget Sound Joint Harbor Operations Center at Coast Guard Sector Seattle.

There are 28, Rescue 21 towers set up throughout the 13th Coast Guard District.

"Rescue 21 has been in the Puget Sound/eattle area for approximately a year and a half to two years now and the system has proved itself to be very beneficial to us," said Smith. "We also have Digital Selective Calling that is part of the system, in essence, that is a panic button on a radio that a mariner can hit and that automatically will send a distress message along with a position of where they are to the Coast Guard."

Smith went on to explain how Rescue 21 works.

"[Our watchstanders utilize] radio monitors and dual monitor displays. On one monitor, we have a chart that shows us where mariners are located according to their lines of bearing from the RFF (Remote Fixed Facility). Anything that comes over Channel 16, which is our distress frequency, will appear red on the screen. Normal mariner calls will be in blue."

"We use this for search and rescue (SAR) as well," continued Smith. "In a SAR case, a mariner may only have the time to call 'help' or 'mayday.' In a matter of a few seconds after receiving that transmission, we are able to take the lines of bearing, which provides a location showing where that person is."

"Rescue 21 also gives us the ability to determine whether calls for help or maydays are real or a hoax," said Smith. "Hoaxes cost the Coast Guard thousands of dollars each year. Using Rescue 21, we are able to determine, through the direction finding system, if the call is coming from water or on land."

Smith went on to add that many times children (and sometimes adults) will stand on the water's edge and will make a call saying that they are sinking or are in immediate distress.

Just recently, the 13th District has endured several hoax calls from children. On one transmission, the child gave his name and a partial address to his house.

"The 'mayday' hoax call was from a young child reporting that his boat was sinking," said Cookson. "Rescue 21 was able to direction find his location to the Maple Valley (Washington) area."

"What this does for the Coast Guard is that it causes us to launch rescue units to go investigate and look in the area where we think the call came from," said Smith. "How we use Rescue 21 on a hoax is it will produce a line of bearing where the call came from, however it won't give us an actual position or it may not triangulate. We may only get one bearing of call based upon its location and how the hills and mountains in the area affect the transmission."

The Coast Guard takes every distress call seriously and will launch assets immediately to the location of the call.

"We will send a boat or helicopter, which costs thousands of dollars per hour to operate to search for the person or persons we think are in distress," said Smith.

"Persons committing a hoax are subject to prosecution as a Class D felony and could be liable for a $5,000 fine including all costs the Coast Guard incurs as a result of the individuals action," said Cookson.

"False distress calls not only cost taxpayers money and place Coast Guard members at increased personal risk, but more importantly, they divert limited resources from mariners who are in actual distress," said Capt. Mark D'Andrea, chief of response for the 13th District.

Hoaxes are not the only thing that presents a problem for the Coast Guard. Man-made and natural disasters such as Hurricane Katrina and the 2007 Pacific Northwest storms caused several communication problems throughout the troubled areas affected by heavy winds and rain. Rescue 21 is able to provide portable, deployable towers for the restoration of communications.

All and all, the new system will close 88 known coverage gaps in coastal areas of the United States, enhancing the safety of life at sea.

"With every rescue made and life saved, we are seeing the return on our investment in Rescue 21," said Admiral Thad Allen, during a speech he made in Scottsdale, Ariz., to the joint Coast Guard and General Dynamics project team about the operational importance of Rescue 21. "Rescue 21 is helping the Coast Guard take the 'search' out of search and rescue."

source: USCG press release

A United States Coast Guard study of the importance of their HF broadcasts states:

"The responding public collectively perceives that the USCG HF broadcasts are essential to their safety. There is no viable alternative to the USCG HF broadcasts because present alternatives are perceived by the public to be out of financial reach. Also, marine weather forecasts available through these alternative sources may not guarantee the same level of accuracy, timeliness, and/or sufficiency as provided by the USCG HF broadcasts."

While the Coast Guard does not have funds necessary to replace all of its HF transmitters, funds are available to replace the 20 transmitters used for weather broadcasts.

The image in the introduction is courtesy of the United States Coast Guard.