The families of some of the seven men who drowned at a popular beach last summer blamed the absence of lifeguards for their deaths as an inquest ended.
Relatives said they believed their loved ones could have survived had lifeguards been manning Camber Sands beach, near Rye, East Sussex, when they got into trouble.
They said they were disappointed the local authority, Rother District Council, did not take up recommendations by the RNLI in 2009 and 2013 to provide lifeguards at Camber.
And, speaking after East Sussex senior coroner Alan Craze concluded all seven deaths were through misadventure, the families said resignations should now follow at the authority. Civil action has also not been ruled out.
Speaking through an interpreter, Arumukam Saththiyanathan, the father of 18-year-old Kenugen and Kobikanthan Saththiyanathan, 22, told reporters at a press conference: "These lives were lost because of the lack of lifeguards.
"It's very disappointing that they continue to deny this fact, that the lack of lifeguards and the failure to employ lifeguards caused these deaths."
Tragedy struck as Mohit Dupar, 36, tried to reach Brazilian Gustavo Silva Da Cruz, 19, as he got into difficulty at Camber last July 24 - but both died.
Then a month later, five young friends, who all lived in the London area and were of Sri Lankan origin aged 18 to 27, drowned at the same beach after being seen playing volleyball in the sea last August 24.
Nine deaths have occurred at Camber in the four years from 2012 - including the seven last summer. But lifeguards were not deployed until after the five deaths last August, despite earlier RNLI recommendations to employ them.
Concluding a five-day inquest, Mr Craze said it was "not known" whether lifeguards would have prevented the deaths. But at a press conference afterwards, relatives criticised the decision not to implement the RNLI's earlier recommendations.
Patrick Roche, the lawyer for six of the seven victims, told reporters he wanted the coroner to acknowledge that Rother District Council had "failed" to implement the RNLI recommendations.
Mr Roche said after the conclusion: "They were young men with huge promise. They were responsible, diligent, loving sons and brothers, and the tragedy for all the families is that that potential will not be realised."
The RNLI's lifesaving manager, Darren Lewis, said there was no legal requirement for local authorities and landowners to provide lifeguards.
He said: "Sadly we cannot guarantee a tragedy like this will never happen again. There is currently no statutory requirement for local authorities and landowners to provide lifeguards."
Rother District Council said it has made improvements "year on year" at Camber in response to risks identified. But even with lifeguards, the council said the sea can be unpredictable.
Dr Anthony Leonard, the council's executive director of business operations, said lifeguards were now in place working alongside the existing beach patrol team.
He said in a statement: "Like their families, we would not want anyone else to have to suffer the tragedy of losing a loved one in these circumstances. Year on year, we have made improvements to the service offered at Camber in response to the risks identified."
The five friends who died last August were Kenugen Saththiyanathan, 18, known as Ken, and his brother Kobikanthan Saththiyanathan, 22, known as Kobi, both of Normandy Way, Erith, south-east London, and their friends Nitharsan Ravi, 22, of Admaston Road, Plumstead, south-east London, Inthushan Sriskantharasa, 23, of Chadwell Road, Grays, Essex, and Gurushanth Srithavarajah, 27, of Elsa Road, Welling, south-east London.
The inquest heard the five men were all fit, healthy and competent swimmers when they died on a sunny day - but beneath the surface at Camber Sands lurked "hidden dangers".
Although rip currents were not a known problem, Camber has sandbars that can catch people out if the tide comes in rapidly, sometimes causing people to wade through water to reach shore, the inquest heard.
Oceanographer Dr Simon Boxall believed the five men got into trouble after heading out to a sandbar to play ball a significant distance out at sea, and then got caught out.
Amid a fast incoming tide, it appeared the men may have panicked trying to help one of their friends and then got into trouble as they tried to get back to shore.
Dr Boxall, a senior lecturer at the University of Southampton, said there also would have been strong currents which would have had a significant impact even on a strong swimmer.
As the men were far out at sea, he said he doubted whether anyone would have seen them from shore, particularly with glare facing people looking out to the water.
Beach-goer Stephen Deacon told the inquest he felt "unnerved" by the underwater sea conditions on the day the five friends drowned at the beach, which can attract up to 30,000 visitors during peak season.
The surface of the sea appeared calm but underwater, the strong current pushed him in and out as he pulled a dinghy with three children inside at sea, he said.
Mr Deacon said he would not have gone to the beach had he known what the conditions would be like.
He said: "It made me feel uncomfortable. It was pushing me in and out. It was like I couldn't control my own body."
Mr Deacon said he saw no warning notices about the nature of the sands, and no flag flying. The only warning he saw was about the possibility of jellyfish, he said.
Tristan Cawte, manager of the Camber Kitesurf Centre, said the sandbars were not dangerous on their own but people, particularly weak swimmers, could quickly find themselves waist or shoulder deep in water.
On the day of the five deaths, Mr Cawte said the water looked "about as safe and inviting" as you would see at Camber without considering the tide and water movement.
Prior to the seven deaths last summer, Camber had no lifeguards. Instead, the area was manned by beach patrol staff whose tasks included reuniting lost children with their parents and dealing with lost property.
But three years before last summer's seven deaths, the RNLI had offered to deploy lifeguards following a risk assessment after the death of Tanzeela Ajmal, 31, in 2012 and a number of near misses, the inquest was told.
The RNLI also offered to provide lifeguards at Camber in 2009. In 2015, beach-goer Thatchayiny Segar drowned at Camber. But lifeguards were not introduced until after the seven men, including the five friends, drowned last summer.
Dr Leonard defended the decision not to employ lifeguards following the 2013 risk assessment, saying the authority's decision was balanced against other factors and that, with statutory obligations to fund, it did not have a "bottomless pit" of money.
And up until 2012, Camber had relatively few incidents since Rother District Council took over responsibility for the beach in 1974, Dr Leonard added.
The inquest also heard that following the deaths of Mr Dupar and Mr Da Cruz last July, Rother District Council asked the RNLI to provide lifeguards but the charity was unable to spare resources at such short notice at the height of the summer season.
Following calls for improved safety, Rother District Council agreed in February this year to allocate £51,000 in its 2017/18 budget for seasonal lifeguard cover this summer at Camber.