Could Searchers Overlook Plane Debris?

>>> WELCOME BACK TO "THE LEAD." AND CONTINUING WITH OUR WORLD LEAD. IT'S ONE THING TO HAVE PICTURES FROM SPACE OF POTENTIAL OBJECTS, QUITE ANOTHER TO SPOT THEM WITH A NAKED EYE AND MUCH CLOSER UP. SO FAR, SEARCHERS HAVE NOT FOUND A SINGLE SCRAP FROM THE PLANE. CONDITIONS ARE SO ROUGH, PLANES COULD BE RIGHT ON TOP OF THE DEBRIS AND MISS IT. >> Reporter: THE SEARCH FOR FLIGHT 370 IS CONCENTRATED ABOUT 1500 MILES OFF AUSTRALIA'S WEST COAST. FIVE COUNTRIES PHOTOGRAPHED FLOATING OBJECTS THAT COULD BE LINKED TO THE MISSING PLANE. AUSTRALIAN SATELLITES DETECTED TWO. THEN THE CHINESE SPOTTED THIS. THE FRENCH PHOTOGRAPHED 122 OBJECTS. THAILAND SATELLITE SPOTTED 300 AND WEDNESDAY THE JAPANESE DETECTED 10. BUT SEARCH CREWS EYEBALLING THE INDIAN OCEAN HAVE NOT FOUND A SIGN OF FLIGHT 370 OR ANY FLOATING OBJECTS BELIEVED TO MATCH THOSE CAPTURED ON SATELLITE. >> IT'S NOT PERFECT. IT'S A COMBINATION OF THE HUMAN EYE AND SERVICE CONDITIONS. >> Reporter: BOTTOM LINE, WAVES AS HIGH AS TWO-STORY BUILDINGS IS THE BEST OPTION BUT NOT A PERFECT ONE. >> ASSUME 100% COVERAGE, MEANS YOU'RE VISIBLY LOOKING AT EVERY SQUARE INCH OF THE SEARCH AREA. THE BEST WE NORMALLY GET ON A LONG-TERM AVERAGE IS ABOUT 78% PROBABILITY OF DETECTION. >> Reporter: AND THAT'S IN CALM WATER. WALDOCH PREDICTS THIS MAKES IT ONLY ABOUT 50%. BIG WAVES ALSO MAKE IT HARD FOR PLANES AND SHIPS TO DETECT OBJECTS ON THEIR RADAR. >> THE WRECKAGE THAT WE'RE LOOKING FOR IS SO CLOSE TO THE WATER LINE THAT OUR RADAR WOULD NOT BE ABLE TO PICK IT UP. SO WE ARE VERY RELIANT ON LOOKOUTS, BINOCULARS. >> Reporter: WITH WEATHER GROUNDING SEARCHERS, TWICE AS MANY SHIPS ARE NEEDED. >> YOU'VE STILL GOT TO GO OUT AND LOOK. ONE OF THE THINGS THAT YOU START BELIEVING IN, IF YOU DO THIS ENOUGH, IS LUCK. >> Reporter: HE SAYS THE BEST