Challenge still stands if you wish to have it self-inflicted, but there is a much more brutal method
"There is a way to get trapped, though: in Diamond and Pearl, never get the Fishing Rod and sell off or use all your Rare Candies. Get a Finneon in a trade from another player. Teach the Finneon Surf, and make sure you have no other Pokemon on your team that can learn Surf, Fly, or Teleport (what is in the PC is irrelevant). Go to the Meister (which requires Surf, which, again, only your Finneon can have) and trade your Finneon for his Magikarp. Congratulations, you're stuck!
The way I listed doesn't require you to give away your last Pokemon with Surf, just the last Pokemon IN YOUR ACTIVE PARTY, which the game has no problem with. Because it can usually only happen in or near towns. Too bad the Meister's on his own little PC-free island..."
Credit goes to jayman7 from the gamefaqs forums
