A "sparkling" woman from Methyr Tydfil drowned in a pool while on a dream holiday in Indonesia with her partner.
Natalie Morris, 29, was found face down in the pool by her boyfriend, Andrew Samuel, in September last year. They were visiting an island off the coast of Bali.
Today the coroner said it was still "unclear" how she entered the water.
The inquest in Pontypridd heard how the couple watched the sunset together "in one of the most perfect evenings you could've had."
Andrew Samuel told the court how they "were making plans for the future."
He said Miss Morris had a few low-alcohol drinks while watching the sunset, a beer with her evening meal and gin and tonics by the pool.
"It was quite relaxed, it wasn't an excessive amount at all," Mr Samuel said.
"We watched a film and I was going to bed, which was quite normal - that I would go to bed first," Mr Samuel told the inquest.
"Nat was going to finish her drink and have a cigarette. She was sat on the decking at the table."
Mr Samuel went straight to sleep in the villa's bedroom, which had the curtains closed, and did not hear anything overnight.
At about 5.30am, he awoke to find Miss Morris was not in bed and searched for her around the property. She was found face down in the swimming pool.
The coroner said police did not find any evidence of third party involvement in Miss Morris's death. A post-mortem examination recorded her cause of death as drowning.
There was bruising to the left side of the top of her head, though there was no fracture to the bone and it could not be determined when it happened, the coroner said.
Alcohol readings taken from Miss Morris's body in Bali were not in measurements used in the UK but the coroner concluded they were "marginally above the legal limit for driving".
He described the death as an "awful tragedy" and reached a narrative conclusion.
"Natalie Morris died from the effects of drowning in circumstances which are unclear," he concluded.
"The evidence does not reveal how she entered the water."