Ben Crawford, 19, had been drinking heavily and had also taken cocaine the night of his death on the Spanish party island in July 2018.
Mr Crawford, of South Elmsall, near Pontefract, was found unresponsive at the bottom of the pool in a private villa, just hours after he landed in Ibiza with a group of ten friends.
Wakefield Coroners' Court heard three friends performed CPR on the apprentice engineer while they waited for an ambulance to arrive, but he tragically could not be resuscitated.
An inquest into his death heard how it is likely a combination of drugs, drink and a lack of food played a part in him passing out at the side of the pool and falling in.
Returning a verdict of accidental death Senior Coroner Kevin McLoughlin said: "It is significant that it's an early morning start and alcohol was consumed since the start of the journey.
"Ben had very little food in his system, the toxicology report found. This may well have had a sedentary affect. It might well be that he fell asleep or passed out and fell into the water."
The group had bought around £3,000 worth of drugs when they arrived in Ibiza and the inquest heard Mr Crawford was a "willing participant" in drug taking and boozing.
Yorkshire scissor master Robert Eaton wins British Hairdresser of the Year 2019York volunteer reveals why she's spending the run up to Christmas in CambodiaThe group, who were all affiliated with Upton rugby league club in West Yorkshire, had travelled to Ibiza to celebrate the 21st birthday of a few of their teammates.
The court heard how the friends had been drinking from early morning of July 7, 2018, in a minibus to the airport.
They continued drinking at the airport and on the plane before clubbing their money together and buying "cocaine, ketamine and pills" when they arrived on the island.
The court heard they had watched an England World Cup match in a bar in San Antonio before heading back to the villa with a group of girls they met that night.
Tommy Owen, 20, told the inquest that around eight of the group were "chilling" in the pool in the early hours of the morning and people last saw Mr Crawford sat on the side of the pool.
He said: "I was either getting in or out of the pool and I felt something on my foot. I looked down and it was Ben. I shouted 'does anyone know CPR?' and people were confused. I swam down to pull him out."
Three pals performed CPR while they waited for the ambulance to arrive, which Mr Owen said took around 45 minutes.
Tragically, efforts to resuscitate Mr Crawford failed and he was pronounced dead at around 6am on Sunday, July 8.
Fears Jo Cox's Twitter account may be deleted as company plans to cull inactive users'If I have nothing to do I'm dangerous' - Jane McDonald ahead of Leeds Christmas show and travel series returnThe court heard the talented rugby player, who previously had a scholarship at Super League club Castleford Tigers, had been "excited" about the "dream holiday".
Heather Thompson, the teenager's heartbroken mum, wept in court as she told how she last spoke to him when he landed in Ibiza.
Mr McLoughlin said a medical cause of death was given by the Spanish authorities as asphyxiation, caused by submersion in water.
A toxicology report found Mr Crawford had 0.78 milligrams of ketamine per litre of blood - 39 times the UK drug driving limit of 0.02mg/l.
Ketamine - used as an anesthetic - is also used as a recreational drug for its hallucinogenic and dissociative effects.
Mr Crawford also had alcohol in his system which was at "one and three quarter times the English drink drive limit".
Mr McLoughlin told the inquest in his experience, he had come across cases of people taking drugs in Ibiza that are "more potent" than in the UK.
He said: "People might only be used to taking drugs in England casually, but have no basis for the strength of drugs in Ibiza.
"Drugs have a greater level of strength than in England. People might think they are buying the same quantity, but it is much more potent."
He said he could not say for sure how Mr Crawford ended up in the pool, but he believed the amount of drink and drugs, combined with a lack of food, could have made the teenager tired and led to him falling asleep at the side of the pool and falling in.