"I'll never forget you." Boyfriend of jet-ski crash victim shares emotional tribute.

Two days on from the untimely death of his girlfriend, 22-year-old Victorian man Thomas Keating has posted a moving tribute to Emily Collie.

“I love you so much Emily and I wish I could just bring you back into my arms,” the Facebook post read. “I’m so broken and I know I’ll never be able to mend.”

20-year-old Collie died in Thailand on Sunday when her jet-ski collided with Keating's off the coast of Phuket.

"We had so many plans for our future Emmy," Keating's post continued. "I love you to bits and I promise I'll never stop and you'll always have my heart!"

Following the collision, Keating told police that strong sunlight had blocked his vision, making it impossible for him to see his girlfriend.

Within moments of the collision, lifeguards pulled Collie ashore and attempted resuscitation, but she was tragically declared dead at a nearby hospital shortly after.

The pair had been dating for 18 months.

"I'll always be your boy and you'll always be my girl," the fourth year plumbing apprentice continued, calling Collie "the most beautiful girl Iv [sic] ever met! Inside and out!"

Following the incident, Thai police confirmed Keating will face a charge of "reckless driving causing death."

Speaking to The Age on Tuesday morning, Keating's sister, Bree Lyon said her brother was cooperating with Thai authorities as much as possible and labelled the collision "an absolute accident".

Alongside numerous photos of Collie and the couple together, Keating ended his Facebook post by saying, "Rest easy Emily I'll never forget you."