[entropy12]

So where is the flotsam? Those 350 seat cushions would never sink.

[cynwoody]

Those seat cushions had a good head start. A lot of time elapsed between when the airplane went in and when anybody had any reasoned idea of where it went in.

Check this out: http://theconversation.com/why-locating-mh370-in-the-southern-ocean-is-so-difficult-24699?_ga=1.154497272.1776735163.1402118941

Researchers dropped ten pairs of satellite-tracked buoys into the South Indian Ocean. Each pair started off only 10m apart. "Within days, the buoys within each pair were already at least kilometers apart. Three months later and some of the pairs are now separated by thousands of kilometers."