Dozens of yards make a huge difference in terms of getting back to the anomaly or debris field area at Niku, but should not so much in an open ocean floor search for the major chunk(s) of a 777.
That leads me to wonder if Phoenix truly understood the criticality of TIGHAR's need for precision, and whether their error is actually within the bounds of reasonable tolerance for open sea floor searching according to more common terms they may deal with. Their
site information says:
An onboard Inertial Navigation System, Doppler Velocity Log, Ring Laser Gyro, and depth sensor combined with an UltraShort Baseline (USBL) System produce highly accurate, repeatable and reliable navigation and positioning of the vehicle.
Which implies more accuracy than my supposition above would expect, as I read it.
This is all educational as to the intricacy of processes involved in qualifying equipment and suppliers and getting an effective search done. It is also very sobering news about what must happen to make any sort of 'surgical hit' occur with true confidence: dozens of yards in tolerance is a no-go.
There may not be a true means of doing so precise a search after all if 'Bluefin' cannot do better - and other brands can't outperform: 'deeper and wider' may have to embrace 'much wider' in such cases, to ensure that the desired areas are re-captured.
Do others than Phoenix demonstrate a more precise technology for subsea placement? I wonder about benchmarking capabilities.