I remember going on the Conception as a diver in its first year of operation (1984?). I was a regular at the 22nd street landing in San Pedro and did many many trips on the Golden Doubloon owned and operated by Capt. Eddie.
I do not recall ever having a safety briefing or their being a roving patrol on any of the vessels in the fleet of SoCal dive boats. Even the dive n surf boat owned and operated by the Mistrial (SP) brothers did this…
With that industry I do not believe it is a case of normalization of deviance as suggest by some… that idea suggests it was once done correctly and over time the discipline of compliance had eroded… I do not believe the regulatory requirements for roving patrol were ever fully implement or enforced .