Richard Anthony Hicks was charged with one count of homicide by watercraft and one count of assault by watercraft for his role in last Wednesday's fatal crash.
Police believe the 46-year-old was under the influence when his speeding motor boat plowed into a sailboat, killing 33-year-old Melissa Protz and injuring two others.
Protz worked as a biology teacher at Assumption St. Bridget Catholic School in Seattle. Her roommate, Maggie Chambers, said students adored her.
"She was teaching kids to care for our planet, love the earth, and give back and be good stewards," Chambers said after the crash.
Protz's father said his daughter worked with dolphins while studying in Australia, and had a deep passion for teaching and the outdoors.
A judge on Monday reduced Hicks' bail from $500,000 to $250,000. His next court appearance is set for August 4 at the King County Courthouse.