A pirate in costume, doing his best Arrrrrrggggh-laden accent shows up at the event, or perhaps the pack meeting before the race:
Pirate(bellows): I be <make up a good name>-something-Beard, the fastest Pirate Sailor on the seven seas! I hear ye be havin' a boat race, here, and I come to run in it.
Cubmaster: Um, well, this race is for cub scouts, but maybe we could let you join us?
P: Grrreat! I'll have ye know that I've never lost a sailing race in all my years!
CM: Really? Wow. You must have a really fast ship!
P: Not Really...
CM: Oh, then you must have a really great crew to win all those races with even a slow ship!
P: Well, No, I...
CM: Hmm, well, then how *did* you win?
P (enthusiastic): Anytime someone dared pass by me pirate ship, we'd let loose the cannon and send 'em to the bottom o' the sea! Heh heh..
CM: I see. Well, we don't do that here. That's cheating.
P: What, ya say that's cheatin'? It's what I usually do, but if ya won't let me sink 'em, then what if we just shoot their sails off so they can't go so fast?
CM: Nope, still cheating. You can't use cannons in a race.
P: No cannons.. <confused> Ah, they we'll ram 'em with the bowsprit! That'll slow 'em down! <grinning again>
<CM frowns, shakes his head>
P: Eh? Not that either? Well, then how do you win the race?
CM: We run out boats as fast as we can make them go, and may the fastest boat win!
P: Arrrr.. But what if I'm not the fastest, then I won't win!
CM: But you'll still have done your best, <turns to the pack> Right scouts? <with a little luck, the scouts cheer> Scouts compete, but we're all good sports- and racing is much more fun when everyone is a good sport.
P: "Do yer best", eh? Hrrrrm- that does sound like a better way to race than blowin' holes in the other boat! Maybe this cheatin', stealin' pirate thing is overrated. I tell ya what-- I'll just come to yer race and see how fun ye can have racing like a good sport. And even I'll give me Jolly Roger to the Den (or sailor?) which sails the fastest ship!