There are fairly technical dimensional requirements related to abalone irons; an iron can't be too sharp, too long or too curved. If you're making your own iron (like the good-old-days), you probably want to check the regulations just to be safe. If you're using a store-bought iron, you're probably fine unless it's really old and/or extensive use has sharpened an edge(s) enough to make the iron illegal. Whether the iron is legal or not is a highly subjective call by the law enforcement officer.

Abalone harvesters are required to carry a gauge for the smallest size that can be legally taken (7" at the time of this writing). That gauge must have opposing faces with enough gauge depth to allow it to fit over the top of the abalone and still make your measurement.

Carrying larger gauges, common among trophy hunters, does NOT relieve you of the need to carry a 7" gauge.

North of San Francisco, use of underwater breathing equipment is illegal when harvesting abalone; divers are limited to using breathhold techniques only. Starting in 2000, it is illegal to bring abalone ashore aboard any boat or floating device that also has SCUBA, SNUBA, or hookah equipment onboard. When the boat or floating device is indeed floating, this new regulation is quite clear: no abalone are allowed onboard if SCUBA tanks are also onboard.

The intent of this regulation is NOT to prevent a boat operator from getting abalone and tank diving during the same trip to the coast. It is intended to prevent getting abalone from a boat unless the tanks are sitting somewhere onshore. Once the boat is high and dry, there should be no problem from the law enforcement types if there are tanks and abalone on the boat; the new regulations specifically refer to "landing" abalone. That said, don't be too surprised if you encounter a warden, ranger, sherriff, highway patrol who isn't quite clear on this distinction. It's always best to know the regulations well enough yourself to be able to explain them (politely, of course) to the confused guy with a gun. Having a copy of the regulations in hand to help in that explanation is probably a good idea until everyone gets quite clear what the regs really mean.