Kristen Fonseca, 16, was riding a rented jet ski near Honolulu. Authorities say she was only going about 10 miles an hour when an Australian tourist slammed into her from behind, going more than 40 miles an hour on his jet ski.
Witnesses say Tyson Dagley, 20, was standing up on his seat just before the crash.
Dagley is being charged with 3rd degree negligent homicide. He appeared in court Friday wearing a neck brace and told the judge he is very, very sorry for what happened.
However Fonseca's stepfather Mario Canton isn't convinced. "I feel like he isn't sorry for what he did to my child. He is more sorry that he is involved," Canton said.
Dagley is being held on $100,000 bail and is set to be arraigned on Tuesday.
The vigil for Fonseca is open to the public and will take place in Vacaville's Andrews Park.