How does your speed seem to compare to theirs? You may be going a bit fast for this time of year Try 1.9 to 2.3 for starters. How far back and how deep are you running your lines? Try running them further back at about 125-200ft in the clear water. Try going on diagonals from close in (e.g. 10ft of water) out to deeper water. Do "s" patterns in your trolling. put your motor in neutral every once in a while briefly and then give it a little gas sometimes they will hit with the change of speed. If it is dead calm try "rocking" the boat as you troll. Change lures frequently (type, size and color) and change the running depth each time too until you start hitting them. Run your boards as far from the boat as practical (depending on boat traffic etc). If all that doesn't work...try fishing in a different area.