Whirlpool Rapids Current Station - Time Discrepancy

[Ernest VB]

It appears that OpenCpn is reporting an incorrect UTC time offset on the detailed current graph for Whirlpool Rapids in Wellbore Channel on Canada's West Coast. The graph is reporting that Whirlpool Rapids is in the UTC+9 time zone, when Whirlpool Rapids is actually situated in the UTC-7 (Pacific Daylight Time) time zone, a discrepancy of 16 hours.

Please see attachment which notes the relevant details of this discrepancy. The version of OpenCpn is 5.8.4.0.

[P_Dub]

Did you hear anything from them, for correcting this?

[P_Dub]

Here is a link to the corrected files. Replace yours with those 2.


https://gofile.me/7apyJ/IkQ1T1GBa

[Hakan]

@P_Dub.
If the built-in Harmonics has inaccuracies maybe it should be replaced by "your" file. Create an issue?

[P_Dub]

Unfortunately I do not want to come into conflict with various Hydrographic Office. Which all wants to promote their own constituents. But on a private person to person, it could be possible. I made more than 4500 stations around the world over the last 25 years. So I know what I am taking about.
So long, Bye

[Hakan]

Ok, thanks for info.

[P_Dub]

Furthermore concerning Whirlpool Rapids current there is 1 hour of difference with Seymour Narrows and not 1h 50m. I don't know where that come from.
Have a good day.

[sv_pelagia]

Originally Posted by P_Dub

Furthermore concerning Whirlpool Rapids current there is 1 hour of difference with Seymour Narrows and not 1h 50m. I don't know where that come from.
Have a good day.

The new harmonics file you posted now indicates proper time zone. Thank you.

According to official CHS tide tables, Whirlpool Rapids SLACK times are 1hr50 min before Seymour Narrow turn to flood and 1hr40min before Seymour Narrows turn to ebb.

[P_Dub]

That I know, but it does not mean that is what it is! What about anyone sailing in this area?

[sv_pelagia]

Originally Posted by P_Dub

That I know, but it does not mean that is what it is! What about anyone sailing in this area?

Rapids in this area hard to predict. Depends on weather as well as runoff from snowmelt up high. We've never found Whirlpool Rapids to be exactly "on time". Usually, we arrive early (before predicted slack) and watch/wait.

[Kelkara]

Pdub ... are you saying that the CHS tables themselves are wrong? I rarely bother with slack tide at whirlpool, so I don't know to the nearest minute when it turns. Despite the name it's not a scary rapid.

However there are some dubious current data out there, for example I do not entirely trust navionics in this region ... I think they get their data from harmonics published by NOAA and not the CHS.

As Pelagia says the currents are very complex in that area ... for example Johnson Strait can have an ebb current all day despite the water level still rising on the flood!

[P_Dub]

I am not saying that they are wrong, I am just stating that the current depends a lot of the wind from the north of Vancouver Island and it is varying a lot.
See the predictions. Remove the .pdf

[Kelkara]

Sorry but I cant open that file on my phone ... yes, wind/rain/snow can all affect the flow, but that obviously cant be built into long term predictions (except maybe as a seasonal average).

What I'm asking is do you have a better source of data than that available through the API provided by the CHS?

[P_Dub]

I thing there difference are base on High and Low waters at Seymour Narrows and not on current time. My Seymour Narrows time are the same at 1 minute difference. That is why the difference.

[desodave]

Originally Posted by P_Dub

I thing there difference are base on High and Low waters at Seymour Narrows and not on current time. My Seymour Narrows time are the same at 1 minute difference. That is why the difference.

Seymour Narrows times are for slack current, not "high and low waters". Can you explain this comment more fully?