Dominicans disdained in Puerto Rico after crossing perilous seas.(Knight Ridder Newspapers)

SAN JUAN _ For two days across the treacherous Mona Passage, Enerolisa Paredes prayed, clasped the wooden slab beneath her until her fingers went numb and kept her eyes tightly shut until the canoe-like vessel packed with other Dominicans finally made landfall.

But the most intimidating part of the harrowing journey came as a shivering Paredes hid beneath the thick brush that grows along Puerto Rico's western coast, barely breathing, for fear that U.S. Border Patrol agents searching nearby would find her.

"I could see them and hear their footsteps," said Paredes, 26. "There was a cow that kept stepping all over me. I kept thinking, `God, please don't let them see me.' "

Eight months later, Paredes has become the mother of a newborn girl who is entitled to the same U.S. benefits as Puerto Ricans. The two have become part of a flourishing immigrant community whose growth is fueling tension between locals and the newer arrivals.

Dominicans have been using Puerto Rico as a stepping-stone to the U.S. mainland for years, but with increasing vigilance over illegal immigration to the continental United States, a more permanent community has settled here.

An estimated 250,000 of Puerto Rico's population of 4 million, or one out of every 16, are Dominican. Although hard data does not exist, officials estimate that about 10,000 immigrants enter annually, and more than half stay.

The overwhelming majority of illegal entrants are Dominicans who venture across the Mona Passage in smuggling vessels known as YOLAS.