If they don't find anything within 24 more hours, I think it may be time to step back and consider possibilities other than a crash into the ocean. The area of ocean where the 777 is reported to have disappeared is relatively densely traveled, and a 777 would leave a whole lotta floating debris (especially if it broke up in-flight). Add dozens of dedicated search ships and aircraft and it becomes hard to believe we could go 72 hours without finding a trace.
There is an awful lot of the reported 'facts' in this case that are not adding up.