A 14-year-old girl died after a wave overturned a speedboat she was in causing her life jacket to become trapped, police said.
Emily Gardner was one of four people thrown overboard but the three others escaped with injuries.
Devon and Cornwall Police are continuing to investigate the tragedy but a spokesperson said: "From the enquiries conducted so far, reports suggest that the boat hit a wave before overturning.
"The four people on the boat were then thrown overboard as a result.
"It appears that Emily became trapped due to her buoyancy aid getting caught on part of the boat.
"The other people on the boat and jet ski riders tried to help Emily but could not free her.
"At this stage in the investigation we are satisfied that there are no suspicious circumstances and we believe that this was nothing more than a tragic accident."
Emily Gardner's family have paid this tribute to her:
“Our beautiful Emily was a caring loving, gentle daughter and sister. She was full of life and had the world ahead of her. She was our diamond, now shining bright in the sky.
"She will be missed and forever in our hearts."
Police have officially named the teenage girl who died following a fatal speedboat incident in Brixham as 14-year-old Emily Gardner from Gloucester.
Emily's identity was confirmed by Devon and Cornwall Police as officials revealed she was trapped underneath a small speedboat after it overturned just outside Brixham Harbour in Devon yesterday.
Police said: "Officers were alerted about the incident by the Coastguard at 12.11pm. Lifeboat crews from Brixham attended and released Emily before taking her to shore.
"Emily was taken to Torbay Hospital by ambulance in a critical condition but was pronounced dead a short time later. Her family have been informed and formal ID has taken place."
The teenager was travelling with two other 15-year-old girls and a 50-year-old man at the time of the accident.
The teenage girl who died after becoming trapped when a speedboat overturned in Brixham has been named locally as Emily Gardner.
Friends and family members are using social media sites to pay tribute to the "beautiful" 14-year-old who is thought to have died while on holiday in the seaside town.
Emily is said to have been with her pals, also named locally, as Holly Pritchard and Gemma Gadsden, who were hospitalised following the accident.
The trio were also with one of their father's, not thought to be related to Emily.
Sharon Ashley took to Facebook to write: "My beautiful beautiful niece love you so much sleep tight xxxxx."
Her uncle, Nick Taylor, added: "Good night my amazing beautiful niece x shine bright like a diamond x."
It is thought Emily lived in Gloucester with her family and attended Chosen Hill School, in Churchdown, Gloucester.
Lynzi Ashley wrote: "Love you Emily Gardner gonna miss you soo much. Get well soon Gemma and Holly Pritchard xx."
Shannon Jade said: "RIP Emily. I hope Gemma Gadsden and Holly Pritchard are feeling better soon thoughts go to you and her family."
Bryony Elizabeth-Gorgina Fenemore posted: "RIP Emily, such a beautiful girl taken from us thoughts go out to all friends and family."
Rita Petita added: "Emily can't believe we've all lost you xxxxxxxxxxxx".
An investigation is continuing today into a speedboat tragedy that left a teenage girl dead and three other people injured.
The accident happened yesterday morning at a marina in the Devon fishing port of Brixham, near Torquay, in the area known as "the English Riviera".
Emergency services were called at 11.44am amid reports that a vessel carrying a father, his daughter and two school friends had capsized.
The rescue operation saw lifeboats, coastguard teams and a helicopter deployed as well as specialist divers.
Police confirmed inquiries into the tragedy were continuing and urged witnesses to get in touch.
A teenage girl has died and three others needed medical treatment after a speedboat overturned in a marina dubbed part of the "English Riviera."
Emergency services were called to Brixham Harbour in Torbay, Devon, after reports a vessel carrying a father, his daughter and two school friends had capsized.
Mark Criddle, coxswain of Torbay's RNLI lifeboat, said crews arrived on scene and found a 16ft speedboat upside down with a girl trapped in it.
He added: "We located the girl and brought her on board the lifeboat where she was immediately given first aid by a doctor and paramedic who were members of the lifeboat crew.
"We took the girl back to shore where she was handed into the care of paramedics who took her to hospital.
"The three other people who had been aboard the overturned speedboat were also taken to hospital after being treated at the lifeboat station."
The deceased's identity has not been revealed, although officials confirmed her next of kin had been informed.
Police confirmed inquiries into the tragedy were ongoing and appealed for witnesses to get in touch on 101 quoting 326 02/05/2015.
A photographer in Devon captured this dramatic footage of the coast road in Torquay being buffeted by strong wind and giant waves.
Some cars can be seen ploughing through the waves and driving rain.
This video was uploaded to YouTube and ITV News cannot independently verify it.
Torquay's main coast road was battered by large waves last night as gales sent spray flying well over the tops of the street lights.
This video was uploaded to YouTube and cannot be independently verified by ITV News.