Are you renting a boat? If you already own a boat, you should already know some good spots, but anyway, if you are renting, that doesn't give you a lot of time to soak the trap, usually you would let the trap soak for a few days for best results; but anyway, if you only have a few hours, just toss the trap anywhere as long as it's able to reach the ocean floor. You're not suppose to set up traps between lions gate and second narrows, so best to stay to the west of horseshoe bay.

also make sure you tie your trap with a marker so you'll be able to retrieve it. have fun