100 Fathoms Under

The super high tech and custom made sonar in the book can now be bought from Garmin for about $600.
The bad guys (and sometimes the main characters and the narrator) use a lot of racial slurs for the natives and the Japanese character.
The Japanese slurs are not too surprising given that the book was written a few years after the end of WW2 and the Don Scott character fought in the Pacific during the war.

The underwater archeology is still relevant.
I'm not sure paper money kept under sea water for a few years would still be usable.

All in all a pretty good adventure, with some OK science.