I know you kids are too young to remember this (I’m in my 50’s) but there were homes in Del Mar that went for the $300’s as recently as the 90’s and are now going for $1.8+.
That’s why it’s unlikely that those who bought during those years and prior will have any problem keeping their homes, or being affected by a crash when it comes to coastal properties.
Still, there might be some hope in picking something up from those who came in later and are in over their heads–should the economy really take a dive again, but even then, there will always be competition for these type of properties.