Prosecutors said the vessel had too many people aboard and was going too fast when it overturned near the Intrepid in 2022.
7-year-old Julian Vasquez and 47-year-old Lindelia Vazquez were trapped under the boat and drowned.
The victims who died were part of a group of family members who got onto the jet boat named Stimulus Money in Elizabeth, New Jersey, for a trip on the Hudson River.
Julian Vasquez was visiting from Florida and Lindelia Vazquez was visiting from Colombia.
Ten other family members, ranging in age from 19 to 53 and all from either Florida or Colombia, were injured, as was the 24-year-old boat captain, who was licensed and is from Elizabeth.
Richard Cruz pleaded guilty to misconduct and neglect.
He faces up to ten years in prison and is expected to be sentenced in January.
* Get Eyewitness News Delivered
* Follow us on YouTube
* More local news
* Send us a news tip
* Download the abc7NY app for breaking news alerts