It's like a rock concert. You hear the feet and swishing arms of 50,000 people. Then there's the endless bands, choirs and orchestras on almost every corner. Your guide tells you there are thousands of firemen and armed American soldiers.
You can smell doughnuts, waffles and coffee sometimes. You feel the sun, wind or rain, on your face. Sweat drenches your shirt. Your legs, lungs and heart work hard. Your feet hurt.
Around 30km everything hurts. You want to give up, but as a team you keep lifting your legs together. Your guide reminds you to eat and drink too. This is when your mindset matters most over the miles.
You keep going until you go under a giant arch your guide tells you exists. You stop when a heavy medal weighs your neck down. That's when you lift your arms and scream "yes"!
That's how I imagine it is for blind runner Tamati Pearse, 24, who I've guided lots over the years. A friend guided me blindfolded while running around a run track so I could "get" Tamati's world. It was terrifying. The trust you need is immense. Try walking with a blindfold on and you'll get what I mean.
I knew at that blindfolded moment that running 42km blind is courageous. Actually, I know that living while blind is challenging too. My nana, Anne Haley, is blind and tells me how frustrating this is.
Tamati has been running for three years and says why he digs this sport.
"I love running because it helps me get outdoors, gets me fit and helps me to expand my social network," he says.
The New York Marathon, on November 4, will be Tamati's fifth marathon. I'll be his guide again and it will be my 22nd marathon.
I've guided several disabled athletes over the years. I'm an ambassador for the Achilles charity, which helps disabled athletes.
Guiding is harder than running solo. Watching out for Tamati's safety keeps me alert the whole race. There's relief when he reaches the end in one piece. Nothing beats the marathon high. That exhilaration of those feel-good chemicals rushing through my body.
It also feels darn good to help a friend.
Tamati and I are among a Kiwi Achilles team doing this marathon. This is special. It is the 25th anniversary of NZ Achilles athletes participating here. It's an important marathon on the Achilles charity calendar every year too.
This city is where the charity started. Every year, disabled Achilles athletes flock to run here from throughout the globe. There are only a few blind Kiwi runners. So, for runners like Tamati, this is a great event to connect with others.
Tamati and Rachel are fundraising to cover their flight costs to NY.
• Their Givealittle page
• Follow Rachel and Tamati's run journey via Facebook or Instagram