Translation:I will take part in the dragon boat competition next year.
"I will take part in the dragon boat race next year" would be correct. Posted on Nov. 19, 2017
I think it should be possible to make "paddling" explicit in this answer. "I will participate in a dragon boat paddling competition next year." is currently rejected whereas the same answer sans "paddling" is accepted.
Should be "a dragon boat competition" not "the" as there are more than one race in the world, and no specific race has been previously introduced.
As a native speaker (admittedly with no knowledge of the dragon boat festival), using "the dragon boat race" would seem the most natural way or saying this.