A man smoked a "legal high" on a fishing trip then went berserk and drowned his friend, a court in England heard.
Christopher Davies, 28, had gone out fishing for the day with his workmate and friend Barry O'Reilly, 37, when they smoked cannabis, Liverpool Crown Court heard.
But after Davies smoked some cannabis - mixed with the now banned "legal high" Spice - he lost control "going off his head" and attacked his friend.
Davies "battered" his victim who was screaming for help, holding his head under the water until he drowned, according to witnesses who called police.
Officers and paramedics arrived and took over attempts to resuscitate, but Mr O'Reilly, a father-of-one, was eventually pronounced dead.
Davies, of Town Lane, Higher Bebington, Merseyside, was jailed for seven years after admitting manslaughter following a "loss of control" at the fishing lake at Claremont Farm in Clatterbridge, on the Wirral, on May 15 this year.
A ban on the supply and production, but not the possession, of Spice and other so called 'psycho-active' substances, once sold openly in 'Head Shops' came into force in England just 11 days later.
But Judge Clement Goldstone QC, Recorder of Liverpool, said the possession of the drug should also now be banned, as he passed sentence on Davies today.
He said: "This is a case which emphasises, if emphasis were necessary, the truly dreadful effects which can be expected from the use of not just Class A drugs, not just of cannabis and other class B drugs, but of synthetic cannabinoids, and other 'legal highs' as they are called, in this case 'spice'.
"I have no reason to believe that if you had not taken spice on this occasion, this crime would have been committed.
"Everything about this case points to a normal friendly relationship between you and Mr O'Reilly, in which you shared a number of interests in common - work, fishing and of course, the use of cannabis.
"I can only on behalf of the right-thinking public in general, and the family of Mr O'Reilly in particular, express the hope that the circumstances of this tragic case will prompt the Government to reconsider its attitude toward the possession of such compounds, as opposed to their supply and production which have recently been criminalised, which are widely acknowledged as being significantly more dangerous than cannabis itself."
The court heard "within seconds" of killing his victim Davies 'came to' and with other fishermen tried to resuscitate Mr O'Reilly before the emergency services arrived.
Davies also told the court he did not initially know his friend had put Spice, which he had never taken before, into the cannabis pipe they were using to smoke drugs.
Senior District Crown Prosecutor Geoff Fryar, from Mersey Cheshire Crown Prosecution Service, said: "Davies was under the influence of the psychoactive drug Spice when he turned on his long-term friend and killed him.
"The effects of these drugs are unpredictable and on occasions such as this, tragic. It is illegal to manufacture or supply such drugs. They can, as in this case, be highly dangerous and should not be taken, however harmless the packaging might seem."
Detective Chief Inspector Paul Denn, of Merseyside Police, added: "During the investigation medical experts working with officers who explained the effects of Spice and they said that the effects can be extreme causing hallucinations, psychosis, muscle weakness and paranoia, as well as many other symptoms.
"Our advice to people has always been not to take any substances if they don't know exactly what's in it or where it came from.
"New legislation came into effect earlier this year making it illegal to produce, supply, import or export a psychoactive substance that is likely to be used to get high and offenders could face up to seven years in prison."