Maptech Support

Offshore Navigator (& Lite) & Chart Navigator (Viewer): General: Offshore Navigator: Application Discussion: 2007 Tide & Current accuracies

      Marc Herrmann
Original Message
(Posted Jan 7, 2007 2:08 PM)

Thank you very much for the prompt available T&C updates for 2007. Much appreciated.
After installing the "patch" update, there seems to be quite a discrepency between the Reference Station and other Stations be they tide or current. As an example, Our reference station is Vancouver BC which, when comparing with Volume 5 Tide & Current Table issued hard copy document seems spot on. However, looking up Point Atkinson as another Station and comparing the hard copy T&C info with what is on the electronic chart is quite different. The same applies to current information between the Reference Station Burrard Inlet and other Stations around BC.
Any help with this would be much appreciated.
Best Regards,
Marc Herrmann
Vancouver, BC

Replies 3 - 12 of 12

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RE(2): 2007 Tide & Current accuracies
(msg #1.2: Posted Feb 12, 2007 3:58 PM)

Has this data ben released yet? I have looked around the site, but see nothing.




      Wayne Pearson
RE(3): 2007 Tide & Current accuracies
(msg #1.2.1: Posted Feb 22, 2007 8:40 AM)

Hi Marc and Jack,
The new tide data has been released, in version 5.08
Version 5.08 is available as a free download, at:
You'll also see some other changes in 5.08 listed on the download page.

Wayne Pearson


      Charlie Hall
RE(4): 2007 Tide & Current accuracies
(msg # Posted Feb 22, 2007 6:49 PM)


On the download instruction page for OSN 5.08 it states that the download contains tide & current data for 2007 and 2008. I have downloaded and installed 5.08 but it does not contain the 2008 tide data. I had recently updated to 5.07d and installed the 2007 tide data with that update. As 5.08 was installing it said "saving current tide data" or something to that extent. I got the impression it was saving my existing 2007 tide data and not overwriting it with the new 2007/2008 data.

I was wondering if the new 2007/2008 data did not install properly because I had already installed the 2007 data... Or if the 5.08 update really didn't include the 2008 data.

How can I load the 2008 tide/current data?

Charlie Hall


RE(5): 2007 Tide & Current accuracies
(msg # Posted Feb 23, 2007 10:57 AM)


I had a similar problem. There is a fix. Charts>ChartList>Advanced Chart Management> Rebuild.

That works for me.



      Ed Lecuyer
Fix for Tides
(msg # Posted Feb 28, 2007 5:37 PM)

If the tides do not appear after the rebuild as suggested, try the following download:

-Ed Lecuyer
Senior Customer Support Manager


      Marc Herrmann
RE(4): 2007 Tide & Current accuracies
(msg # Posted Apr 6, 2007 2:04 PM)

Hi Wayne;
I updated the patch you suggested (5.08) and I still have significant differences between the base reference station (Vancouver, BC) and any other tide or current stations in BC. How can I get this fixed? The base reference station which is Vancouver is spot on as per the published Tide & Current Tables Volume 5.
Any suggestions would be greatly appreciated of how to get this problem fixed.




      Wayne Pearson
RE(5): 2007 Tide & Current accuracies
(msg # Posted Apr 9, 2007 8:34 AM)

Hi Marc,

To reiterate what Ed Lecuyer said, in the forum discussion specifically about the 2007 Canadian tide and current data:

"Maptech provides digital tide data (via Offshore Navigator) for a limited number of Canadian stations. This is done to provide accurate and complete predictions in US waters. Thus, the only stations in Canada that appear in Offshore Navigator are those that are necessary for neighboring stations in US waters.

Maptech has never had tide & current data in all Canadian waters. Maybe with the recent changes announced by the Canadian Hydrographic Office and Digital Ocean/NDI, we will consider doing so as we continue to refine and improve our products."

Wayne Pearson


      Robert Early
RE(6): 2007 Tide & Current accuracies
(msg # Posted Jun 13, 2007 5:30 PM)

Hi Wayne,

I notice a "current speed" inaccuracy in comparing the Cape Cod Canal RR Bridge. On June 13th, when the flow change at slack goes toward Flood, the Eldridge Table and
give the time as 8:48 (pm) but the Offshore Navigator, V.5.08 with the ClrCache appplied gives the the time as 19:46 or an hour earlier.

OSN has -5 hour correction (from UTC) given to agree with the computer ET zone. The Station Number is OSN is given as 2166 - "Cape Cod Canal railroad bridge"

I had noted the discrepancy first on June 29th at 3:18 (am) when Flood begins, but OSN noted it as 2:18 (am).

The discrepancy is is an hour off on each webb & flood for this location. Is there a correction for this?




      Wayne Pearson
RE(7): 2007 Tide & Current accuracies
(msg # Posted Jun 19, 2007 11:16 AM)

Hi Robert,

I've forwarded your update question to the production department.
I'll add more to this reply when I know more.

Wayne Pearson


      Wayne Pearson
RE(8): 2007 Tide & Current accuracies
(msg # Posted Jun 21, 2007 9:39 AM)

Hi Robert,

This is a matter of applying Daylight Savings Time to the data.

NOAA web tidal current and tide predictions are in Daylight Savings Time.
Check the bottom of the page in your Eldridge and check the note concerning Daylight savings Time.

The printed NOAA data is EST. Eldridge copies the government tables. Maptech's tidal current and tide predictions agree spot-on with the government paper data. Add an hour, and it agrees with the web data.

Check the bottom of the page in your Eldridge and check the note concerning Daylight savings Time.

Wayne Pearson


Replies 3 - 12 of 12


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