I usually use 1/2 ounce but depending on the surf or tide you may have to use up to one ounce or 1 1/2 ounce weights. off shore you would need 2-3 ounce weights. Fresh water you usually use 3/8 oz.
I was using 3oz on Tybee last fall in the surf. That's as light as I could go and keep bait in place.