I dove the stretch from top of Trancas to Zeros like crazy in my teens and up and they are good when the viz is on. Stand on the cliff with polarized shades and you'll know if it's clear viz or not, reefy or not, kelpy or not, etc. Leo Carrillo is a super popular dive spot but I avoid windsurf/kitesurf spots for obvious reasons. Above county line to Mugu Rock, Deer Creek and random reefs are more fickle (viz), way creepier, but sometimes open up and the bottom structure is insane, unlike anything south of Neptunes Net. IMO best thing to know is what swells/wind/etc make the viz good at the spots you like to dive and you'll enjoy it way more. There's a simple formula for every dive spot just like surf spots.