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Hello Herman (again),

I guess I last bought a Nautical Almanac when I was at University (1967-1969)... Reeds Nautical Almanac.

I understand that there is much more information in an official Nautical Almanac than merely the 'daily pages' I publish. Besides no one should ever rely on my publications if their safety at sea is at stake.

So why did I finally purchase the HMNAO NP314 Nautical Almanac? I want to cross-check my figures with it. Others have already done some cross-checking, but I am simply curious if I will find a discrepancy.

Actually (I'm boasting a bit here), I did find a discrepancy in the "Astronomical Phenomena 2021" and on 21st April 2021 James Whittaker, HMNAO Senior Analyst at HM Nautical Almanac Office, UK Hydrographic Office, replied to me:

Dear Andrew,
You are completely correct and thank you for bringing this to our attention.
The values on page 49 are the complete answer, page 47 has only one of the rise times.
The issue was missed during compilation, and it subsequently slipped through the verification process as well.
We have updated our procedures to put additional safeguards in place to ensure this event is less likely in the future.
Kind regards
James

I just wonder if I can spot a mistake in their Nautical Almanac. The challenge is on!

Kind Regards,
Andrew