Laguna has a marine protection officer that was hired by the city of Laguna Beach. It is her job, among other things, to cite those who disobey the posted laws. The LG's will call her.
Snorkel: Doesn't have to be on your mask, can be in pocket, etc. I have been asked to show my snorkel on a couple of occassions before entering never upon exit.
Buddy: Odd buddies is okay 3, 5, 7, 9, etc; just not solo. Not that it's right, just that it satisfies the ordinance.
Of course the looseness of the language of the ordinance is such that divers and LG's interpret them differently, as do different LGs. I've heard instances of (mainly summer hire) LG's requiring the snorkel to be attached and odd buddy groups not being allowed to dive, but this is far from the norm based upon my personal experience and from what I've heard.
Viloation of these ordinances are also a MISDEMEANOR offense, not just a ticket & fine, but a summons to appear in County court. Cases are heard by County Judges not LB city judges. I've heard of at least one (solo) case being successfully defended and/or reduced from a misdemeanor to an infraction. But that's a not a chance I'd recommend taking.
18.21.060 Penalty for violations.
The violation of any of the provisions of this chapter is punishable as a
misdemeanor. (Ord. 506 (part), 1962).
-Garrett