what state and what lake are you fishing? that lake sounds alot like one we have here in northern arizona.

with your powerbait rig you should use #10 sinker over a barrel swivel with a 18" to 24" inch 2lbs to 4 lbs leader ( 3 lb is fine) with a size 12 to 14 treble hook and just put enough power bait on the hook so that it floats nicely. also you should have several colors of powerbait so you can change colors every 20 or so minutes untill the fish start biting and which ever color they bite that will be the color that should work all day long.

also when fishing power bait its better to be stationary try to keep the boat as still as possible or better yet what i do is beach the boat on the bank and fish power bait from the bank.

then with your mepps and rooster tails use size 1/8 oz or smaller I use alot of 1/16 oz rooster tails. roosters tails and mepps are great lures for trout for casting from a boat. I do alot of trolling with rooster tails let the lure trail behind the boat about 50 to 60 feet and run the boat around the lake at about walking speed ( 1 to 2 mph).

try these things and let me know if it helped you catch some fish.