Country coastlines changing big time (is this a data issue)

Hi, 

I stumbled upon a video where the guy had traced around the coastline of Cuba,  he then went back i think 2 months later and the whole coast line has changed.  Its not the only place.

As a software engineer myself I believe it could be just the data getting input or the algorithms that are skewing the data.  Not knowing how Google Earth is coded or how Google Earth gets its data I am reaching out to the community in the hope that some developers /QA people working on Google Earth can explain the changing coast lines.

Here is the video 
skip video to 5mins40 to start


best regards

P

Another video 29th Jan showing more coastal changes 

again jump to 5mins and start watching,  clearly shows very different coast lines in a short period of time.