I just joined this forum and since I live and sail in Chile
, I started reading all posts related. That's how I found your post from 2 years ago with no answer. I can only guess the lack of answers was because the way you posed your concern. See, the way you are approaching sailing is wrong. You can't try to predict things in such a large scale. Much less keep safe from them. It would be like trying to predict all odds before riding a car on a highway!
Anyway, answering your question, Rhian and Andy were ready to leave Robinson Crusoe aboard Zephyrus when the tsunami hit. They helped and saved some people that night, and left before the second wave hit. Here's their blog>Robinson Crusoe Island, Juan Fernandez | Smiling Footprints
I hope whatever you guys choose to do after retirement
, you approach it with abandon, for life is short anyway.