BOSTON (CBS) – On a day when millions of eyes are fixed on the Boston Marathon, these are the 236 that are most important.

They are the Race Spotwatch and Spotters Network, the eyes of the Boston Marathon for WBZ-TV from start to finish.

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“You not only have a front-row seat for the celebration, but you’re a key part of our broadcast. You help us bring that drama out on the course to the everyone who cannot be there to see it in person,” Lisa Hughes told the Spotters Network team during their visit to WBZ-TV. “I want to thank you for the very important work you’re going to be doing.

“For 32 years, volunteers like you have been our eyes and our ears from Hopkinton all the way into Copley Square,” she added.

Since the Race Spotwatch was established by Fred Tressler (an Olympic coach and running industry expert) and former race director Tim Kilduff in 1985, they’ve covered over 3,000 miles of the Boston Marathon. Their teams have been the eyes for 55 marathons in total, including the races in New York and Pittsburgh, as well as the 1988 US Women’s Olympic Trial Marathon.

There will be 118 spotters for the 121st Boston Marathon this year, representing 16 different high schools and colleges throughout Massachusetts. Of those 118 spotters, 91 will be assigned along each mile along the Marathon route and at the finish line while the other 27 remain in the WBZ studios in Brighton. Together, they are responsible for tracking the progress of runners and relaying accurate and timely information back to the WBZ control room.

The information they pass along is not just who is leading the races and what times they pass, though. The spotters also pass along observations for Hughes and the rest of the WBZ crew, everything from which runner looks determined to catch up, who has the biggest (and loudest) support group, and who looks like they’re going to have a tough time crossing the finish line.

“What they do is enhance our coverage,” Hughes said. “They are the eyes in the course when the race starts.”

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Race preparation for the spotters begins weeks in advance, when they gather at WBZ-TV in Brighton for an hour-long info session. That’s where they learn what their jobs will entail when race day arrives.

Race day is when the real fun begins.

For the spotters, their Marathon Monday starts bright and early at 7 a.m. at WBZ in the Spotters Network Studio. They each head to their respective mile markers, and go through separate rehearsals (broken up into three groups) before a final dry run just before race time.

The command center for the Spotters Network in the WBZ-TV studios. (WBZ-TV)

The lingo is much different than one would expect. Men are now “boys” and women “girls” to avoid any confusion. Spotters radio in to the studio as soon as they see the lead vehicle approaching; identifying themselves, what mile they are located at, and which race they are reporting. They count down how many meters away the approaching runner (or group of runners) is until they pass by, which is signaled with a “Mark NOW!”

Luckily, the runners are not referred to by name but instead the number on their bib.

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Hundreds of people give their all to make WBZ’s Marathon coverage the best there is, and the spotters are an integral part of it all.