If you have comments, questions, or suggestions, don't hesitate to leave a message. I always appreciate feedback.

Unknown, uncertain, not found?

I have tested every square and am confident that the internal structure is sufficiently proven to offer a conversion. However, I am aware that there may be contradicting sources out there.

If you think that any of the information is wrong, imprecise or doubtful, please let me know and help me improve the program by providing your thoughts or charts and documents that may be helpful.

Write a message

Due to the European General Data Protection Regulation I am not allowed to provide a contact form using unencrypted channels. Since this website is not collecting any personal data whatsoever, it would be overkill to implement SSL and TLS only for the sake of contacting me. Therefore it is your own choice wether and how you encrypt your message to me.

Any information you send will be stored in my IMAP mailbox and on my personal computer. I will never share any information with a third party. If you want me to delete any previously sent messages, please send me an e-mail. (Absurd, eh?)


Where can I download an offline-version for my travels?

At the moment there is no offline-version to download. At some point I might create one, but it will be without any visual representation on a map, obviously.

Can I download your database with all the coordinates?

No, you cannot, because there is no database. There are roughly 4 million squares in the grid. Using various algorithms I am able to calculate all squares based on just a couple hundred lines of geographical data. All calculations are done on the fly and are not persisted.

Why did you do this?

I originally built this service for my friend Jerry at helping him making sense of positions in u-boat logbooks. And I did it for the enjoyment of solving the puzzle.

What are the costs to run this website?

I pay about 150 EUR per year for domain and web space.

Will it stay free?

Yes it will. There will never be advertisements or fees. But I can't guarantee that the service will be always available. If I have to shut it down however I will release the source code under an open source license.

Why should I donate?

I don't expect people to pay for a free service and I won't be disappointed if you'd rather save your money. If you find this service valuable or useful, please send me feedback or donate. If you think, this is just a big pile of crap, don't write me, because I don't care.