Two people, a 17-year-old boy and a girl aged 12, have died after they were pulled from the water at Bournemouth beach on Wednesday (31 May).
Joe Abbess and Sunnah Khan were taken to hospital but later died from their injuries.
Eight other people who were also rescued from the water, were treated at the scene, but no others were taken to hospital.
An inquest into both of the deaths opened today (5 June) and the coroner ruled they died of drowning.
The inquest heard Joe Abbess, 17, and Sunnah Khan, 12, died of drowning following “speculation” they got caught in a riptide off Bournemouth beach.
A man aged in his 40s who was on the water at the time was arrested on suspicion of manslaughter.
He was released under investigation pending further enquiries.
On Thursday night (1 June), a pleasure boat was impounded by police who it's thought are looking into the vessel as part of their investigation into the deaths.
Police sealed off and carried out a search of the Dorset Belle at Cobb's Quay Marina in Poole.
A spokesman for Bournemouth, Christchurch and Poole Council confirmed that the boat is not licensed by the local authority.
Latest from Dorset Police
Police say neither of the deceased young people or anyone else pulled from the sea at the time of the incident, was involved in any collision or contact with any vessel in the water.
Detective Chief Superintendent Neil Corrigan said: “We continue to keep an open mind around the circumstances that have led to the tragic death of two young people in the water off the beach.
"Our thoughts remain with the families of those young people.
"As with any investigation of this nature, we have to look at all factors connected to the state of the water. One of those lines of enquiry has involved the pleasure boat, which was in the area at the time of the incident.
"These enquiries also include examining wind, other weather and general coastal conditions at the time. We are working with experts from partner agencies to understand all of the factors and this will take time to establish.
"We continue to support the families of Joe and Sunnah and they are being kept updated by specially trained family liaison officers about our investigation. I would ask that the police investigation is allowed to continue without further unhelpful speculation around the circumstances of the incident, and that there is respect for the families of those who have died so tragically.
"I would continue to appeal to anyone at the beach at the time who witnessed the incident to come forward and talk to us.”
Officers say the beach was particularly busy at the time of the incident, and are asking members of the public with any photos or footage to get in contact.
Watch the Dorset Police press conference
What happened at Bournemouth beach?
Multiple emergency services including Dorset Police, the RNLI, HM Coastguard, and two air ambulances were called to the beach at 4:32pm on Wednesday 31 May.
Ten people were recovered from the water.
Joe Abbess, 17, from Southampton, and 12-year-old Sunnah Khan from High Wycombe in Buckinghamshire were airlifted to hospital.
They died from their injuries a short time later. Their families have been informed.
Speaking on Thursday Dorset Police Assistant Chief Constable Rachel Farrell told a press conference there is "no suggestion" of people jumping from Bournemouth pier or of jet skis being involved in the incident.
An investigation into the circumstances surrounding the incident has been launched with Dorset Police working alongside the Marine Accident Investigation Branch and the Maritime and Coastguard Agency.
What has the RNLI said?
Speaking on Thursday 1 June, a spokesperson for the RNLI said: "We would like to offer our condolences to the family and loved ones of the two young people who sadly lost their lives yesterday at Bournemouth beach.
"RNLI lifeguards along with volunteer lifeboat crews from RNLI Mudeford worked with emergency services to provide search and rescue, and casualty care.
"This incident is now in the hands of Dorset Police and we will not offer any further comment at this point."
What has Dorset and Wiltshire Fire and Rescue Service said?
Crews from Westbourne, Springbourne and Poole fire stations from the BCP area were called to the scene in support of other agencies in their attempts to rescue the casualties involved.
"Any lessons that need to be learned will be" say BCP Council
Leader of Bournemouth, Christchurch and Poole Council, Cllr Vicki Slade said: "I want to add our severe condolences to the families of the children who lost their lives.
"Our thoughts are with the families of the young people who were in the water.
"It must have been a really terrifying experience for everybody.
"The services worked incredibly well together. Our staff on the beach all rallied round to support the emergency services.
"We're grateful to the public for clearing the space so quickly, and we are making sure that the staff from the beach office are getting the support that they need.
"Today and over the weekend, there are additional staff available for the public on the beach as it is busy. We are making sure that the RNLI are very visible and there are teams to support people and make sure that they feel safe on the beach.
"Bournemouth remains a really fantastic place to visit and this incident needs to be investigated properly. We are confident with our partners that any lessons that need to be learned in the future will be learned.
"There are specific rules relating to the buoys out in the water, but there is no evidence to suggest that any of those rules have been breached."
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