Edition 5 is now relaeased!

We have now released the 5th edition of the NDTT. The main change is related to compliance with Norwegian in-shore diving regulations as issued by the Norwegian Lbour Inspection authority. The main changes in NDTT took place in Ed 4. You may see the the comprehensive list of changes (relevant for both editions) through subpages to this webpage. You may download the publication free of charge from this link.

A hearing and invitation of the latest (5th) edition was closed June 30th 2019. All comments from the hearing was in Norwegian language only and the editors have decided to comment on these in Norwegian. If you would like to read the commets and our replies, you may download this document.

About this website


This is the official website of the Norwegian diving and decompression tables (NDDT). The editor of the webpage is the principal author (Jan Risberg) and you may contacct me through e-mail. The co-authors of NDTT are not responsible for the content of this website except for the official PDF-versions of the NDTT.

The NDTT was issued in its third revision in 2008. The fourth edition was released Jan 15th 2017 and the fifth edition was released September 2019.

 The third revision was authored by Arne-Johan Arntzen, Svein Eidsvik and Jan Risberg. Arne-Johan Arntzen has decided to withdraw from further participation and Svein Eidsvik regrettably died during summer 2015.

Jan Risberg has been granted the rights from the publisher (Barotech AS) for further development of the tables. Olav Eftedal and Andreas Møllerøkken co-edited the fourth and fifth edition.  The English verion is available for download - please use the link indicated in the far most right part of this webpage.

This site will not update issues related to the third (or earlier) editions of the NDTT. Please contact Jan Risberg as detailed below if you have questions related to earlier editions.

The text on this website remains the sole responsibility of myself (Jan Risberg)

Errors and improvement proposals

The tables will be revised as errors are identified and improvement proposals received. We heartly wellcome comments to the tables through e-mail. A specific page in Norwegian language on this website has been dedicated for presentation of areas under consideration. A similar page is available in English language, but priority is given to keep the Norwegian page updated. Accordingly there may be topics covered on the Norwegian site that is not presented in English language.

Contact and purchase

I may be contacted through e-mail.

The printed version of the tables may be purchased through e-mail to Western Norway University of Applied Sciences, Diver Education (Høgskulen på Vestlandet, Dykkerutdanningen).The cost is NOK 250 each + postage.

A PDF Version of the final English Version may be downloaded through this link.

The publisher of the 3rd edition of the NDTT (Barotech) has informed that there will be no further support for the third and earlier edition. Please contact me by e-mail if you have furhter questions related to the 3rd (or earliker) editions.

Files for download

Official/Public Version: