I cottage on an extremely weedy lake, so I know what challenges your facing. All the above posters gave great suggestions, methods I regularly use in those conditions, which I shall not repeat but emphasize their value.
I have two lures that I also employ in addition to the above:
1) Bucktail Jigs
Most use it for enticing walleye out of weedbeds, "ripping" it from the bottom and letting it sink. This method can also be very successful for bass. In weedy lakes, most fish use the foliage as cover and ambush prey from within it's hiding - bass are no different. A bucktail jig gets you to those spots, the base of the plant. You can also drop pockets with accuracy.
2) Jointed Floating Rapala (J7)
For those areas where there is a little column of fishable, "weedless" water - even if it's just under the surface, a Jointed Floating Rapala is a bass killer. I suggest something small like a J7 as it rides higher and for some reason doesnt really get hung up on weeds, you can even burn it right through some thick stuff. The tight wobble of the J7 is irresistable to bass. Firetiger is my favourite and bass kryptonite 8)
But let the fish porn do the talking; top was taken and released on a 3/8 ounce bucktail green/black, bottom on a firetiger J7 Jointed Floating Rapala, both in thick, thick weeds:
Good luck in the tourney!
reefrunner