Prosecutors say 64-year-old Stephen Schneider was drunk last month when he struck a channel marker in the Barnegat Bay.
Both siblings, who were 7 and 9 years old, were ejected from the boat and into the water.
They were taken to a hospital where they were pronounced dead.
The crash occurred at night but police say lights on the marker were working properly.
----------
* Get Eyewitness News Delivered
* More New Jersey news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Download our connected TV app