Project "Duikboot"

Written by Frans Beckers and Walter Cloots
Last Update: 29.03.2017
Total records: 86938

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Duikboot - Search Form

The project’s subject

Submersible (EN) = Tauchboot (DE) = Duikboot (NL)

DUIKBOOT is the name of a database about German U-boats of the Second World War era.
The database holds information and facts related to ordering, keel laying, launching, commissioning, important events during the operational life of the boats (incl. operations during the Spanish Civil War), their loss or their end.

What is it?

DUIKBOOT is a database, which means this project concerns only data: no paintings or photographs, no colourful ocean maps, no drawings, and also no full-text stories. Just data.

Why is the project’s name “DUIKBOOT”?

Because the two authors of the database are from Flanders, and in this region of Belgium one speaks Flemish (officially the language is called “Dutch”). Our (and now also your) database since many years bears the name DUIKBOOT, the Dutch word for submersible. As the project required a name with the Historischen MarineArchiv (HMA), for simplicity’s sake the original Dutch name was maintained.

Some information about the authors

As stated above, we are two Belgians.
Around 1975 our interest in the subject evolved into a real leisure time occupation. We are no professionals, no history scholars, just enthusiastic amateurs.
Frans Beckers was a (strict but just) police-commissioner in a big city and
Walter Cloots an engineer in electro-mechanics, leading a warehouse management team in a Belgian telecom company.
English (and German) is a foreign language to us, but we bet Dutch is a foreign language to 95% of the HMA-users/readers...


Mid 2011 – with thanks to Thomas WEIS (aka “TW”) as most friendly and supportive middleman – contact was made with Thorsten REICH (aka “t-geronimo”), to offer DUIKBOOT to the HMA as possible project.
Till June 8, 2012, the day DUIKBOOT was made accessible to HMA-users with nearly 67.000 records in the database (*), HMA’s technical division expended almost a year of spare time to program the search and filter functions hiding behind the search form.
(*) The present total number of records is listed just below the date of the last update and indicates the database is alive and constantly being extended.
We owe the technical division of the HMA that the database is being offered as it is (with the multiple search possibilities).

Why “YET ANOTHER” website with U-boat stuff?

There already are, in no particular order, for example:
- Deutsches U-Boot-Museum ;
- ;
- ;
- Uboats in the Bahamas ;
- …
Correct. And we don’t want to compete with either of them, nor with other presentations of the subject; neither do we want to be guilty of plagiarism.
We don’t want to continuously compare „our“ database with information presented by others. We base our data on own research and evaluations, without – however - dismissing critical comments regarding the contents of our work.

Yes, but why then still an additional website on the subject?
Because our database, using a search form, can be searched for many and various facts:
- partly by entering free-text (commanding officers, text-fields with further information on events);
- partly with drop-down menus offering what can be searched for in the database field concerned (events, U-boat groups);
- or by using whatever combination of entries.


The database provides no information as to the source used for particular information, except when the information was extracted from radio messages (“TF” – “FT”).
That we nevertheless made a real effort to provide correct data might be shown by the following examples.

Records related to the Spanish Civil War are mainly based on the Bundesarchiv-Militärarchiv (for short: BA-MA; Freiburg i.Br, Germany), archival records RM 20/895; /897; /899; /904; /905; /1222; /1223; /1247; /1249; /1251; /1252; /1253; /1257; /1259; /1260; /1262: /1312; /1316; /1389; /1439; and /1440.

Information regarding commanding officers comes mainly from officer lists (‘Rangliste’) of the German Reichs- and Kriegsmarine (editions for 1918, 1925 and 1926, 1929 till 1932, and 1935 till 1944); the war diaries of the U-boats and the U-boat commands; a WASt-list; and the evaluation of the contents of 40+ books, principally “Die deutsche Kriegsmarine 1939-1945” by W.Lohmann and H.H.Hildebrand.

At this point the HMA-project Deutsche Crewlisten im 2. Weltkrieg must be highlighted as well as the great and generous support received from Fernando Almeida.

All war diaries (of individual U-boats and U-boat commands) available on microfilm from the U.S. National Archives and Records Administration (NARA), Microfilm Publication T1022, finding aid No.2 “Records relating to U-Boat Warfare, 1939-1945”, 1985,, were acquired and evaluated. Where these where illegible, they were replaced with paper copies of the relevant pages of war diaries held by the BA-MA.

Various radio messages, copied and deciphered by the Allies (Series ZTPG, ZTPGM, ZTPGR and ZTPGU), are available from, for example, the U.K. National Archives (Kew, Richmond, U.K. - formerly these archives were known as The Public Record Office), Record Groups DEFE3 and HW18. All these radio messages were acquired as microfilm copies, read and evaluated. The huge catalogue of the U.K. National Archives can be searched online: If you want to learn which records were already consulted for DUIKBOOT then look through the PDF-list:

Are we aware that author x in his/her book y brings other information on the subject than our database?
Perhaps not, but presently (Mai 2017) we have access to a small naval library with the following books:
What they bring on the subject of U-boats was read and evaluated.

Bestsellers, even when additions/corrections did appear since their publication, remain
“Axis submarine successes” by Prof. Dr. Jürgen Rohwer (continued as HMA-project „ASS – Axis Submarine Successes“ by T.Weis) and
“German U-Boat losses during World war II” by Dr. Axel Niestlé.
Should you be more interested in technical matters, then have a look at the numerous books by Eberhard Rößler.

The study of Allied primary records provided a problem: the Allies gave U-boat positions in geographical coordinates, not in grid-positions. At the BA-MA and the Library for Contemporary History (Bibliothek für Zeitgeschichte, for short: BfZ, Stuttgart, Germany) all available grid maps (Quadratkarten) were studied, evaluated and a conversion tool was created that can convert a grid map position into latitude and longitude, and vice versa.
Hereafter you find a list giving which grids (at least partly) are shown on which grid maps:   Maps held by the BA-MA are marked “+”.
Please note: the Marine Archives of the Library for Contemporary History (the BfZ, curator: Mr.T.Weis) is a real treasure cove with lots of things worth knowing or worth looking at, including re. U-boats.

Today, the internet also provides conversion programs, for example

The preceding paragraphs give you a rough idea which sources were – and are! – being used in creating the database.

Next to written sources there is an exchange of facts and ideas with interested parties studying related topics. One long time canadian friend, Eric Zimmerman, has been researching for many years operational details of U-boat history and often contributes to DUIKBOOT in the fields of U-boat attacks on shipping and ASW attacks on U-boats, particularly those carried out by aircraft. Eric was co-author to Norman Franks of “U-boat versus aircraft” (ISBN 1-902304-02-0, published 1998).

Another friend, David Sibley, regretfully passed away May 2014. He also should be remembered here. David’s research was directed towards the fate of Allied/British merchantmen damaged/sunk by U-boats and especially the fate of the (surviving) crew members. David’s support often made it possible for us to learn how events were seen by Allied sources, in comparison with their description in German war diaries.

DUIKBOOT’s weaknesses

- Information about flotilla’s is basic;
- Data covering periods a U-boat was not on patrol (but in port or in a shipyard) is lacking;
- Missing times are cause for errors when sorting the database by date and time;
- Columns FEIT and REFERENTIE hold text in Dutch;
- …?…
If progress is made eliminating weaknesses, it will be communicated through HMA’s forum.

Using the database & languages

The offered search form and the explanations accompanying it already provide the reader an idea what he/she can search for. When you want to exploit the offered search possibilities to the full, then it is highly recommended to read the “Explanations re. the database” zu lesen:
This document is written in such a way that it should be equally legible in English, German and Dutch.

The user’s choice of the language having his/her preference (select the appropriate the flag for EN, DE or NL) defines in which language the search form and descriptions will appear on screen or can be selected. As many abbreviations are used in the fields FEIT and REFERENTIE (explained in 3 languages in the “Explanations re. the database” (see above for a link to this document) the information in the database – built in Dutch – might already be legible in its current form for users with a basic knowledge of English, German and/or Dutch.

Perhaps in future the fields FEIT and REFERENTIE will be offered in all 3 languages.

Forum Marinearchiv

Enjoy the use of DUIKBOOT in the HMA, and thank you in anticipation for your questions or remarks in the forum (FMA), where you can enter your additions, corrections and observations.

The first field in the search result for DUIKBOOT is a unique record ID-number. Please, PLEASE, provide this number in your forum contributions.
AAs a help function, one may select the number preceding each record. This will automatically open a new topic in the FMA column „Deutsche Kriegsmarine – U-Boote“ having the relevant ID-number as subject. Only limitation: you need to be a registered forum member.

To the Forum Marinearchiv :
When you do not receive a participation/reaction from us on your questions and/or observations re. the subject in the forum then this does NOT mean we’re not interested in your contribution but only that we’re simply not able to follow-up and react to all forum-contributions.

With best regards from Belgium,
Ihr Frans & Walter (Forum-Name: ARANTALES)

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