Like a few have said, in a brine in the cooler. If you do not want to carry salt water to the truck go to the store, put cooler in back of vechicle, get a couple of 15lb. bags of ice and a box of salt, pour salt over ice. You would be surprised how much colder it will be instead of just ice and water.
Good luck at the tournament 
And yes Fisherman Tim, the weigh-in ends promptly at 4:00PM and we go by the clock at the weigh-in, not the one on your wrist. Weigh-in is from 3:30- 4:00
Whiplash, the tournament is still named after Mary Parisi.
It's the best Blue Fish Tournamant on the east coast, started out with three people making a five dollar bet amongest themselves for the biggest bluefish many years ago.