Revision history

The revision process - 5th edition 

There were two main reasons for a new revision of the NDTT in 2019:

  • Inaccuracies and errors reported in the fourth edition should be updated
  • Changes in Norwegian legislation for inshore diving should be incorporated

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).


The revision process - 4th edition


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:

  • Medio april: The principles for revision should be presented in oral for stakeholders and interested (completed Feb -16)
  • Medio may:Finalize a public releasable draft of NDTT Rev 4 and release this requesting feedback (Completed April -16)
  • End aug: Principle author to finalize draft of NDTT Rev 4 for review within board of editors (Completed July 2016)
  • Medio sep: Final deadline for board of editors to finalize review process
  • End sep: Initially considered date for public release of NDTT Rev 4. Regrettably we have to pospone this.
  • Medio oct: A new draft (Rev D7) has been produced and released for public review. Final date for comments: Dec 15th 2016.
  • Nov 30. 2016. Meeting With "Standard Norge" Expert Group receiving input from Norwegian stakeholders. 
  • Jan 15th 2017. Date of Public release for the official 4th edition of the NDTT. Completed Jan 15th 2017
  • March 2017. Expected release date of printed tables (in Nowegian and English). Completed Feb -17.

Third edition: Revision comments


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

Draft versions

Draft NDTT Ed 5