For just the “maintenance cost of $50,000” per year they could hire 3 sharp 3rd world guys at a PC watching the news wire for earthquakes. They then make a quick line of site judgment call of the wake probability and sound the alarm. No underwater pressure sensors (that are unable to tell the difference between a 4 and 40’ wave) needed.
Magnitude 9.0 Earthquake - OFF THE WEST COAST OF NORTHERN SUMATRA
A great earthquake occurred at 00:58:55 (UTC) on Sunday, December 26, 2004. (snip)
The earthquake occurred at 7:58:55 P.M. EST (New York, U.S.A.), that is 2:58:55 P.M. HST (Hawaii, U.S.A.); and that is 7:58:55 A.M., Dec. 26, 2004 in Sumatra / Aceh and in Phu Ket, Thailand.
bd476's post was 47 minutes, 31 seconds later, which is a quick response, for a bunch of volunteers, here. The time in Sumatra / Aceh and Thailand, was 8:46:26 A.M., Dec. 26th.
If it could be done, here, it could have been done over there --- an Internet connection that is more than likely available to most news / weather / maritime stations --- already quite a lot of sophistication that was unavailable to earlier generations.
I would not be blaming the destruction of life on "being cheated out of life's lottery by greater powers that could have done more."
There is no one to blame. There is a lesson, taught many times, awaiting all who will learn.