Hi everybody!

It was just recently that I've discovered that my tide data from wxtide32 isn't correct. It is different from the data from official sources in Croatia (based on xtide program). I was reading a bit about the issue and it seems that wxtide32 is derived from an older version of xtide which is a UNIX based program. I have tried to use a different program (WTides) but it doesn't seem to work with RM. Is there a chance WTides could work with RM or, if not, what should I do to get correct tides? Is there a way I could get a raw (csv) data from somewhere and use it instead? WTides doesn't seem to have an option to export it's source tables... What should I do?

Hi Riba,
Your best option I think is to try and source some data for the times you need in CSV format. You don't necessarily need a lot - just enough to use for your tracks, and 15 minute (or even larger) intervals will probably be enough, depending on how much tidal movement you get. RM will interpolate (using a simple linear interpolation) between supplied points.
You can import tide data into RM from a file with the format <time>,<depth>, where depth should be a positive value in metres. Be aware of local/UTC time issues when importing - there is an option to select when importing, so you need to know if your source is local or UTC and, if local, make sure the time zone is set correctly.

Matt

Thanks Matt :)

Good info as always Matt.
Riba does have a point when asking for more sources then WXTide though. In my neck of the woods (or waters...) the tidestations in WXTide seem correct, but they are few and far apart. The Norwegian coastline is approx 100.915 km long, so a few more stations then the 17 listed in WXTides would be nice. (The program actually list 18 stations in Norway, but one of them is not in Norway at all.) For Sweden there are no tidestations in WXTides at all.

It may simply be a matter of changing the harmonic constants. There is a thread in CF here www.cruisersforum.com/forums/f134/strang...-wxtide32-81922.html that natters about it. As long as you arent publishing the data you produce there is nothing wrong with using more accurate constants from the local hydrographic authority.

T

Hi Matt!
I did what you said and created my own tide stations out of .csv text files. I imported tracks with these and everything looks fine but when I open the track later to edit in the tide part it says none instead of the tide station it was loaded with. Also, sometimes the tide line isn't drawn correctly but the "moving axis" are correct as I move the mouse pointer over a tide graph.
Now, one funny thing:) As I was writing this I went to see how it looks today concerning these problems and there was no first problem? It is OK for me now, but I left this written for you if it could tell you something. The other problem is still present but I believe RM has correct values (that moving axis show) even though the graph line isn't drawn correctly.

Hi Riba,
It would be interesting to see an example, perhaps a screenshot or your .rmdb workspace file if the problem remains? (email or upload to a file sharing service and send link to This email address is being protected from spambots. You need JavaScript enabled to view it. ).

Matt

Here is a screenshot of the edit track window where you can see the tide line going differently than what the axis show...

And it is this Tide station...