I think that's what I was trying to say here? Edited my post to clarify. If you acquire (thru legitimate channels) the tables from an agency that are copyrighted, you can used them and even fair-use reference them. The OP is who for some reason was annoyed that the tables were copyrighted for some reason.I believe you'll find this is not true. There is probably little jeopardy, but it is illegal. You can (for example) quote an NDL from a PADI RDP (that is "fair use") but not reproduce the entire RDP.
I suggest you check the copyright law and not trust what your friends tell you or what you "read somewhere."
IANAL but I'm married to a professional librarian, and they deal with this stuff all the time.
If the OP wants copyright free material, then likely that's going to require going back to the old Navy or NOAA tables since as US Gov't produced works, they should be public domain. But.... that means losing out any 'value' that the various agencies have attempted to add in their versions.