They had data of "discolored water" in an area 3nm from where the seamount actually was, on a chart not normally used for navigation

It is true that they did have the chart available, and that they would have been far more prudent with regard to their intended track (and speed of advance) had they known about even something as vague as discolored water while planning the voyage. But implying that the fault was either limited to the crew or obvious in retrospect is unrealistic IMHO.

The crew should have done a more thorough scrub during their voyage planning process, but the NOAA and Navy offices that prepare charts should also have done a better job of ensuring that hazards to safe navigation are listed on all of their charts (but especially the ones intended to be used most frequently!), not just one or some of them.

I'm not sure if this is meant to contradict my comment somehow, but I think we are saying the same thing -- read differently, it sounds like you might be suggesting they don't even need the new data. Whether on VMS, or notice to mariners, or whatever, what they had was a report of discolored water. Different, therefore from new data revealing underwater topography.

Removed redundant and pedantically incorrect extra use of word "new".