Sutthipong Laphutama, 18, was reportedly riding a rented bike with another member of the team, Auttapong Noikamsin, 13, on the back.
Auttapong suffered a broken collar bone, and will undergo an operation at the OrBorJor Hospital this afternoon.
On hearing the news Phuket Provincial Administration Organisation president Paiboon Upatising and Vice-Governor Sommai Preechasil rushed to the hospital to offer sympathy to other members of the Bangkok team.
The boys’ coach, Kingor Suansan, told media that the two were due to join the rest of the team at the Nong Harn lake next to Nai Harn beach to cheer on their team in the final rounds of the canoe competition, after which they were all due to leave Phuket.
However, Mr Kingkor said, the two sneaked away and borrowed the motorbike – which had been left at their hotel in Sai Yuan after being rented by the parents of another team member – to buy some items at the shop nearby.
From his bed in the OrBorJor Hosipital, Auttapong said the bike went out of control on a bend on the Laem Promthep-Nai Harn, which had become slippery from rain.
The bike hit the wall of a house, killing Sutthipong instantly. Neither of the two was wearing a helmet at the time.