Standard rafts (or at least ones I've been in) are around 3-4m, not far off the "more than 2 metres". No idea how big ones from aircraft are though. Conversely it seems massive for a buoy.
Having a look online shows that Boeing 777 life rafts are 30 feet (9.1m wide). Thats greater than 5 times the surface area of a 3m wide circular object.
I think its fair to say they aren't life rafts. A 2-3m wide buoy doesnt seem that 'massive'? http://en.wikipedia.org/wiki/Buoy