Once in a lifetime might be overstating it. A handful appeared near San Diego in 2024[1], and several were observed in New Zealand and the Canary Islands last year. Wonder if this is a case of surveillance bias as a result of easier communication or an actual increase in appearances
The figure of speech is about a typical divers lifetime. I believe you’re confusing it with “once a generation,” which refers to the collective human experience type of rarity.
I’ll be honest, I’ve never heard that phrase in that context. My only real frame of reference is the 1981 Talking Heads hit single which I always took to have the “once in a generation” meaning. What’s a diver’s lifetime?
[1] https://www.theguardian.com/us-news/2024/nov/15/oarfish-cali...