we've come a long way from: <a href="https://www.youtube.com/watch?v=NAsM30MAHLg" rel="nofollow noreferrer">https://www.youtube.com/watch?v=NAsM30MAHLg</a><p>(incidentally research into automated tidal calculation was sponsored by the Royal Navy, because they didn't want their ships to get stuck off somebody's coast, in plain sight for hours after having rendezvoused, just because they missed a suitable tide for landing marines...)