Woman dead, boy saved in Qld boat mishap

A toddler spent around three minutes trapped under a capsized vessel before he was pulled from the water in a Queensland boating accident that has claimed the life of his grandmother.

The 73-year-old woman died when the boat flipped at Curtis Island, off Gladstone, just before 7.30pm on Tuesday.

Her 14-month-old grandson was unconscious when he was rescued from the under the boat and relatives conducted CPR on him until emergency services arrived.

Critical care paramedics then worked on the toddler for 20 minutes before airlifting him and his 34-year-old mother to Rockhampton Base Hospital, the RACQ Capricorn Helicopter Rescue Service said.

A fourth person on the vessel, a 32-year-old man, was uninjured.

Flares were used to raise the alarm, with nearby boaties going to help before rescue crews arrived.

Authorities are determining what caused the boat to capsize.

The vessel is expected to be retrieved from the water later on Wednesday.

A report will be prepared for the coroner.