On the East River just across from Rikers Island sits a barge officially called the Vernon C. Bain Center. But every judge, layer and inmate in New York knows it as The Boat — a giant, floatingSometimes when the wind blows, you can feel it list just a little.

It is here that I first meet Shadu Green in June 2009. He is locked in a day room, still wearing the T-shirt and jeans he had on when he was arrested three weeks earlier.

In here, “every day is horrible,” he says, leaning against one of the green walls. “I mean, I try not to show emotion because in here, you show emotions and they eat you alive.”

Green, 25, is charged with a series of misdemeanors after getting pulled over in his car. But he doesn’t have to be here. He has been granted bail. A judge has decided he is likely to show up for court when he’s supposed to — if he can post a $1,000 cash deposit. A bondsman has offered to post the money for him, for a $400 nonrefundable fee.

Green doesn’t have $1,000. He doesn’t have $400. He doesn’t have 44 cents to mail a letter to his mother asking for bail money. jail docked in the Bronx.

So like thousands of inmates here and hundreds of thousands nationwide, Green is left with two options: He can fight his case — but he’ll have to do it from here, behind bars — or he can plead guilty and take the 60-day sentence prosecutors are offering him and go home.

The only problem, he says in a hushed voice so other inmates don’t hear him, is that he believes he’s not guilty.

“It’s not a choice,” Green says, “because if you don’t have money, you have to stay here. It’s ruining your life either way you put it. Either way, you have to be here.”