The Seaking Catching Day is a fishing competition to see who can catch the largest Seaking. Contestants may use any rod, reel, or lure they like and may catch as many Seaking as they like—but only one may be entered in the competition and it must be caught using a Lake Ball.
Competitors can also have one of their own Pokémon registered to assist them in their catches. In the case of a tie, the competitors and their registered Pokémon will face off in a Pokémon battle to determine the winner of the competition. The first prize winner gets a trophy, as well as a year's supply of chocolate candy. At the end of the tournament, contestants must return the Seaking they caught to their natural habitat.