Two women and a man were rescued in waters at Sharks Cove in Haleiwa Monday, according to Ocean Safety officials.
The women, ages 19 and 20, suffered apparent head injuries and multiple abrasions, according to Emergency Medical Services officials. They were hospitalized in serious condition.
The 18-year-old man suffered minor injuries.
EMS officials say paramedics were called to Sharks Cove at around noon after the three people were swept off a reef by a wave.
A high surf advisory is in effect for the north shores of Oahu, Molokai and Maui as well as the north and west-facing shores of Kauai until 6 p.m. Monday.