Garmin Tide Times

[DGR]

I have an odd problem with the tide prediction on my Garmin 188C. Yesterday, the Mapsource software on the PC gave me 2.0m until 14:43, yet the Garmin unit - using the same BlueChart database, gave me 2.0m until 15:18 - when there was definately NOT 2.0 metres of water in the harbour ...

Anyone got any ideas why there would be a difference?!?

DGR...

[Pete7]

Have you got the latest operating system software release? there was an update a couple of months ago which JW kindly down loaded onto a spare card for me. PM me your address and I will loan you the card. Update took 2 minutes and self installs.

Also having a problem with a 188c at the moment. Not sure if its the internal battery failing causing the set to forget were it is or the cable from the antena to the head unit which has a poor connector so the set fails to get a good signal.

This might help:

http://www.rib.net/forum/showthread....highlight=188c

Pete

[DGR]

Pete,

Thanks for that - I've done an update fairly recently, but Garmin have sent out three or four this year so far for the 188C!! The latest one I've got is from June and is version 6.10 - I'll check to see if I did upgrade it to that version, and then see if it works!!

Cheers,

Dylan...

[Hightower]

I've had conflicting info from my Garmin 182c about tide times, but its usually an hour out! When I first found the prob I though, hey....Must be the Time not being set right, but it was! I had to offset the time manually to compensate, then the next time it went the other way and had to reset the correct time. I wondered if it the units deciphering of the satelite signal ment the sometimes it goes to UCT instaed of GMT. Weird!

[DGR]

I've done the update to the 188C hardware, and high tide and low tide times and heights seem consistant - but its still off in-between!! Today the PC software was telling me I had to be out of the harbour by 13:00 (2.0m of water), but the 188C was telling me that I had an extra half hour!!

When you select tide stations on the Garmin - what does it actually do? It seems to take a while (20 - 30 seconds) to 'find' the stations - which seems longer than it would need to just look up info on the memory card.

While I accept that I can be a little simple at times - so it could well be operator error - but I still don't get why (or how) there can be a difference in the same dataset!!

Anyone got any ideas?

Dylan...

[Shaggy]

Hi Dylan
Give the tide station and a date to compare with my Mapsource and 168 Sounder.

This might help determine if the tide chart predictor it self is wrong.

Shaggy

[Outnabout]

Have noticed recently that my tide times have disappeared from my 188C. Two things may have caused this and I'm not sure how to resolve it.

First was an upgrade to ver6.10 software (unlikely though as you all seem to have tide times with 6.10).

Second is a change from a pre-made Garmin chart chip (out of date now) to a blank Garmin 32Mb chip onto which I've downloaded my maps, routes and waypoints from v7 of the Blue Chart maps using current Map Source software.

I have a feeling the problem is related to not copying a tide map onto the blank chip but I don't know how to do this and can't find a link on the Garmin site. I've had a look through previous postings but can't find any tips there.

So if anyone knows a solution I'd be very grateful.

Regards

Colin

[Shaggy]

Hi Dylan

This should read:

Give me a tide station and a date to compare with my Map source and my 168 Sounder.

This might help determine if the tide chart predictor it self is wrong at that tide station.

Hi Colin

The tides have to be uploaded as a map to the GPS, I would download your working maps and routes, waypoints and tracks from you GPS into map source, ensure all your working maps are present under maps on the left hand side.

Then select the tide and marine services from the drop down box (top right), then select the tide map area by using the map tool, once selected you should see it added to your map selection on the left under maps something like:

Europe BlueChart Atlantic v7.5 Tides and Marine Services 131 KB

Then upload this with your other working maps, routes, waypoints etc to the GPS/ Card.

So your map selection will look something like this (Note the top one):

Europe BlueChart Atlantic v7.5 Tides and Marine Services 131 KB
GB1121 (500000) BlueChart Atlantic v7.5 137 KB
GB1123 (500000) BlueChart Atlantic v7.5 102 KB
GB1149 (75000) BlueChart Atlantic v7.5 60 KB
GB1156 (75000) BlueChart Atlantic v7.5 49 KB
GB1165 (75000) BlueChart Atlantic v7.5 92 KB
GB1178 (200000) BlueChart Atlantic v7.5 140 KB
GB1179 (150000) BlueChart Atlantic v7.5 107 KB
GB1267 (75000) BlueChart Atlantic v7.5 83 KB
GB1410 (200000) BlueChart Atlantic v7.5 113 KB
GB147 (A) (15000) BlueChart Atlantic v7.5 37 KB
GB147 (B) (12500) BlueChart Atlantic v7.5 40 KB
GB147 (C) (12500) BlueChart Atlantic v7.5 7 KB
GB154 (A) (35000) BlueChart Atlantic v7.5 76 KB
GB154 (B) (35000) BlueChart Atlantic v7.5 12 KB
GB18 (5000) BlueChart Atlantic v7.5 59 KB
GB2345 (A) (15000) BlueChart Atlantic v7.5 32 KB
GB2565 (150000) Atlantic BlueChart v4.00 122 KB
GB2565 (150000) BlueChart Atlantic v7.5 93 KB
GB2649 (500000) BlueChart Atlantic v7.5 59 KB
GB2655 (325000) Atlantic BlueChart v4.00 150 KB
GB32 (A) (20000) BlueChart Atlantic v7.5 5 KB
GB32 (C) (12500) BlueChart Atlantic v7.5 104 KB
GB32 (D) (12500) BlueChart Atlantic v7.5 14 KB
GB777 (75000) BlueChart Atlantic v7.5 74 KB


Also I have a spare BlueChart Atlantic v7.5 update disk including Tides and Marine Services 131 KB, I would be happy to pop it in the post to you if you or anyone else PMs me with their address.

I have 3 spare disks now after sending a complaint email to every email address I could get my hands on at Garmin, as they failed to reply to my previous two emails about not receiving the 7.5 update disk.


Shaggy

[DGR]

Shaggy,

Thanks for that - I can give you the PC based data, and I'll get the same data from the 188C tomorrow.

At Barmouth on the 16th October (a topical date!!)

High Tide is 4.79 metres at 07:58 and
Low Tide is 0.70 metres at 15:26.

Between these, there is 2.0 metres of tide in Barmouth Harbour at approx 12:10 (1.99m).

Let me know if this matches with your dataset/prediction!!

Cheers,

Dylan...

[Shaggy]

Hi
Results taken from my Mapsource:

Barmouth
16/10/2005 07:58:07 4.79m High
16/10/2005 15:26:14 0.70m Low

Time at 12:10 giving 2m of water

So the results are the same.

I have checked St. Ives against the BBC coast and sea page times in GMT

BBC have St. Ives as
0023 Low 0.4
0613 High 6.9
1240 Low 0.5
1834 High 7.1

Garmin show:
00:56 Low 0.55
06:46 High 6.50
13:15 Low 0.77
19:05 High 6.41


Did you see the disclaimer in the Notes on Marsource?

This product has been derived, in part, from Admiralty charts and publications with the permission of the UK Hydrographic Office and the Controller of Her Majesty’s Stationery Office. All rights reserved.

WARNING: No National Hydrographic Office has verified the information in this product and none accept liability for the accuracy of reproduction or any modifications made thereafter. No National Hydrographic Office warrants that this product satisfies national or international regulations regarding the use of the appropriate products for navigation.

Cheers Shaggy

[Outnabout]

Shaggy you're a star. Instructions followed, job done and tides back as before.

Many thanks and a pint awaits if you're ever in the Alton area!

regards

Colin

[Shaggy]

Hi
No worries Colin glad I could help, don’t rely on them too much, looks like there is quite a bit of difference between Garmin and BBC.

Just checked easy tide and this concurs with the BBC posting therefore I would conclude that the Garmin aint right but better than nothing

http://easytide.ukho.gov.uk/easytide...ictionLength=7

Shaggy

[DGR]

Shaggy,

Cheers for that - I guess it means I won't be relying on the Mapsource data!!

I'm still not sure why the PC and 188C don't agree though - not that it really matters if they are both wrong anyway!!

Dylan...

[Shaggy]

Dylan
I would check the time settings for your GPS UCT etc.

Shaggy

[DGR]

I've checked all the obvious things - but today I've checked what the 188C reckons is happenening in October - High and Low tide times are consistent, as are the tide heights - but the shape of the tidal curve is different on the 188C - it says that I've got 2.0 meteres of tide at 12:35pm (12:10pm on the PC).

How weird (and rubbish) is that?

Either way, I think I'll be using UKHO data from now on!!

Dylan...