There were two main reasons for a new revision of the NDTT in 2019:
The errors identified in the fourth edition have been comparatively few and small. However, the Norwegian Labour Inspection Authority has changed regulations for inshore diving which significantly has affected decompression procedures. Most importantly, bottom time restrictions - identical to UK and NORSOK - has been enforced. Secondly, the regulations have specified requirements for multilevel diving.
A summary of changes may be read at this webpage. A hearing was completed June 30th. All feedback has been reviewed and the editors have summarized their responses in this document (Norwegian lanugage only).
A detailed change log in Norwegian Language is available for download at this website. Major changes are presented in the file "Revision history/change log" on the right panel of this page. Further revision has taken place since this change log was written (the change log was issued July 2016 while the latest changes were implemented December 2016). We do not have the capacity to translate the Norwegian change log document (for changes implemented after July 2016), however these changes are of a comparatively minor nature. The reader should be aware that though the change log document refers to Revision 6 of the US Navy Diving Manual, the authors have reviewed Rev 7 of the USN Diving Manual and included those changes considered relevant (this was completed during Dec 2017). The most relevant change from USN Diving Manual Rev 6 (2008) to Rev 7 (2016) is the use of VVAL 79 parameter set rather than VVAL18M.
This was the original timeline intended for the publication of the fourth edition of the NDTT. The last bullet point identified the delay regarding completion of the process that took place during 2016:
COMMENTS AND CORRECTIONS
This website was redesigned Feb 2016. I will not have the capacity to transfer content as web-based text, but I have saved the relevant pages in PDF format.
The English version of the NDTT was first issued 2008. The first print held a number of errors (see a summary here) which were corrected in the 2nd printing. You may review the file listing the detailed list of corrections. You may download a corrected version of Table 1.
Once again - please remember that the errors listed here were corrected in the second print Nov 2008