You say the guys were in their late 20's, no doubt they'll be down to the lake again but this time with little his chav brat in tow to sail his radio toy boat, because now it'll be Cool.
When said brat has had a little time to start enjoying his toy and chav dad is now cooing how proud he is of his son, run the toy over with your huge model sending it to the bottom, chav brat will intantly burst into tears.
Then you can scream " how do you 'blinking!' like it!!!"
or you could simply pull out your jammie and pop a cap in his "bottom"!