The 3rd World Puddle Jumping Championships take place at Wicksteed Park in Kettering today.
Organisers have asked competitiors not to have fizzy drinks over fears it could give them an unfair advantage.
The competition is part of the Autumn Playday series of events aimed at encouraging children and adults to get outdoors.
Other activities otday include an Ugly Veg competition.
Donations of tins of food are being requested for the Salvation Army and toys for the Syria Refugee Crisis.