Is it all based on true events?

I wouldn't have thought so.

http://centuryofobscurity.blogspot.com/
Reviewing films 100 words at a time.

Yes, a family managed to get off the invisible volcano-island that lies in the middle of the Bermuda Triangle. When the family got back to the States, their youngest child had been cured of diabetes and the father never yelled at his kids again. The oldest child was able to breathe under water, and the wife became an OB-GYN who delivered babies while staring thoughtfully into the distance. And they lived happily ever after. Unfortunately, despite their best efforts, they were not able to direct NATO search parties to the island's location to rescue the other castaways.