Matthew Webb had been at a restaurant and bars after visiting a factory in Bruges with fellow staff from Smith Brothers Stores (SBS) building supplies before he fell into a canal in January last year.
His inquest in Wakefield heard friends only noticed the 30-year-old, of Arthington Terrace, Hunslet, was missing when he failed to return to the hotel they were staying in.
After he disappeared Mr Webb’s family appealed on social media for information.
The body of the “sociable” former Woodkirk High School pupil, who couldn’t swim, was only discovered on February 19 – nearly a month after he was last seen.
Assistant coroner Jonathan Leach said: “It would appear that after Matthew became separated from his colleagues he entered a canal. How he entered it and when and where is not clear, nor is the level of alcohol.”
He said the water would have been bitterly cold at that time of year and Mr Webb only had on a short-sleeved shirt.
Writing on Facebook last month, Mr Webb’s sister, Rachel, paid tribute to her brother, saying: “What I would do just to have you back here with us, just to talk to you one last time and just to have one last hug. It still doesn’t seem right and
“I don’t think I’ll ever understand why you where taken from us.
“A year ago today I lost my best friend and my brother and I miss you ever single day.”
The assistant coroner recorded an open verdict.