We have all had a time on a lake when every fish caught is small. It is assumed by many that the big ones must be somewhere else in an adult-fish only spot. Don't be so fast to assume this. Consider what must be true when fishing in a tiny pond like my neighborhood pond of only about 4 acres. All the fish are in those 4 acres at all times, yet sometimes I'm catching all 10 - 14 inch bass and other times most fish are over 15 inch. What can be learned from this is that the big ones are always there even when I'm only catching small fish. Therefore, what might need to change is the presentation.
If every fish you catch is smaller than desired, first try a new presentation before moving on. Try up-sizing your bait. Sometimes it should be increased to the size of the fish you were catching. Swim baits are often a great choice for this. Also try topwater. Remember that many of the larger fish have been caught before, and it's not an act they want to repeat. A subtle top water presentation might make the difference. Be ready for a pair of lips to slowly slurp up your presentation. Finally, you should consider a slower and more erratic approach. The big ones didn't grow to such a size by expending energy chasing their food. Then if you still catch only smaller fish, perhaps it is time to move on.