For sure all here really appreciate your efforts.
While looking again on your post #98
http://www.pprune.org/7698544-post98.html
blade was there...
Most of us with some underwater experience know well that bottom
of the sea is living beast. Sea can spit out that blade next year, or even
after some more time. Take another attempt while passing by next year,
your luck may be there (like mine, more than once).
The other way now, or after future miss with side-scan, is to go with
parametric sub bottom profiler, but that toy cost bit more than side-scan,
and cover of area is much slower.