Lowrance plotter tidal module bugs - JOINT ACTION PLEASE

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bluedragon

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Quite a number of us on this forum have been complaining about bugs in the Lowrance plotters’ tidal module, whether used with Navionics or NauticPath charts. I first brought this to the attention of Silva UK in Sept. last year, and then after no progress made an issue of it at their LBS stand in January. Much of this history is on the forum. There are a number of issues:

a) When metres are chosen as the depth unit, the tidal guage “T” pop-up reads a fathom value, and vice-versa

b) On certain random dates in the month the tidal data behind the T icon becomes corrupted and displays for example three LW values and one HW, or one LW and three HW. There is no obvious pattern to this, and the remainder of June looks OK. My plotter does however show this effect on the 3, 17 & 18 July 2006 if I wind the date forward. Would others check this please? It only seems to happen with the Navionics charts, not NauticPath, but check please.

c) As recently reported by forum members the current module (C icon) gives incorrect readings unless DST (daylight savings time) is switched off i.e. the unit must run on UTC. My observations in the Bristol Channel this week confirm this, BUT ONLY WITH THE NAVIONICS CHARTS…even with DST off I couldn’t get the NauticPath chart to correctly give the transition between ebb and flood. It seemed to be an hour ahead of itself. Other areas might be different…let us know.

I have been in touch with Lowrance USA for months on issues a) & b) and although the contact I have there is a VP of Sales, he doesn’t seem to be able to get things done. I suspect I’m a lone voice and if nobody else complains it gets low priority. So all you 3500C and 3600C users out there (and other Lowrance plotters) get e-mailing! The customer service contact addresses at Silva UK and Lowrance USA are:

lowintl@lowrance.com

Iain.Henderson@silva.ltd.uk

If enough of us complain, we might get something done. I believe a software update will fix the problems, and the fault lies with the plotter, not the charts…at least for Navionics (I've seen their raw tidal data and it seems OK).
 
Navionics chart on Navplanner on PC indicates one non-tide on each of your dates by --:-- ie only 3 tide points on those days. The same should happen on 1/9/06, 6/10/06 and 14/10/06. Will check on plotter over w/e and see if plotter shows same (same chart SD loaded into Navplanner as plotter) or the erroneous display you indicate on these dates. If so it would seem to confirm your suspicion of coding error on the Lowrance software.
Can you expand on "seen their raw tidal data." I am trying to find time to plot time/height differences in a neap/spring/neap cycle against HO harmonic constants. They do not appear to use HO data. I posed the question elsewhere whether perhaps they are extrapolated from a limited list of standard ports. Does your sighting of their "raw tidal data" give a clue as to the source of the Navionics data?
And yes will follow up with Lowrance and Silva (thanks for addresses) as soon as got my head as far as possible around the different errors.
 
EXCELLENT. I didn't think of that. You might have cracked it!! Just looked at Milford Haven and Avonmouth tides and they have 3-tidal point days on the dates in question or the day before (except the 18th). The plotter software is probably looking for four tidal points per day, and when it only finds three it creates one from adjacent data! Please suggest that to Lowrance...and Navionics might like to know also. They are aware of this issue at some level and it's in their interest to have Lowrance solve it. The data I saw was on the Navionics stand at the LBS. We looked at the data the suspect days on their PC display and it was fine. I can't help answer your question on the data source though, I'm sorry.
 
Your observations pretty much mirror mine.

My one query sn on the odd dates you quote where you say there are only 3 tides displayed.

I can see a few days where the graph goes slightly wonky Ii.e. it will miss out on the red or the blue section - but the times given in the text below seem OK (so long as you are happy with it pulling the last tide time from tomorrow or whatever if appropriate)

I can see that there is a slight bug in the colouring of sections on the graph when there are only 3 tides in the day - is that what you are referring to - or have I missed something else ?

I have compared various tidal algorithms for calculating the tides (for Milfor Haven at least) - and I can't find one that actually matches the Navionics ones - but all are within what I consider a reasonable time difference (but as said elsewhere it would be interesting to know how they calculate these)

Thanks for teh email addresses - I'll write once I get my quill sharpened ...

Best wishes
James
 
OK - I see the issue is more than I describe - e.g. Milford Haven - August 19th 2006

Has a funny looking graph and the tide times underneath are:

HW 3:24 14.4 ft
LW 9:48 8.3
HW 16:06 16.9
LW 16:42 16.7 (rather high for LW !)

Should be more like:
Milford Haven
Saturday, 19 August 2006

03:28 16.5ft
09:51 8.5ft
16:09 17.0ft
22:37 8.0ft
 
OK - my effort at a letter below - will see what response I get

=======================================
I have recently bought the 3600 plotter and the Navionics charts for the UK.
On the whole I am very pleased with the unit and I think both companies are to be congratulated on producing what is a highly functional solution at a reasonable price.

My one gripe is with the tidal data – there seems to be a number of bugs which (as a software developer) I would imagine are fairly trivial to fix – and certainly in the UK market detract from the product.

I am aware that you have been notified of at least some of these issues Sept 2005, so I would hope that these minor fixes could now swiftly be rolled out.

Issue 1 – Tidal heights
Applies to both Navionics and NauticPath chartes.
When metres are chosen as the depth unit, the tidal guage “T” pop-up reads a fathom value, and vice-versa.
If the units are set to feet then the unit functions correctly. Unfortunately normal use in the UK is for metres – so this causes some considerable confusion.
This would appear to literally just require a reversal of metres and fathom units in the setup screen – so I can’t believe would be tricky to fix

Issue 2 – Tide and current times
When using Navionics charts
These cause me considerable confusion to start with – but eventually I believe the issue simply relates to the Daylight Saving Time (DST) setting. In the UK at the moment we are on BST (which is GMT + 1 hr) – so the logical setting would seem to be to set DST for the UK. However if this is done all the times are advanced by an hour (I would assume they were OK in the winter when there is no DST)
Fortunately there is a workaround in that if you set the DST setting to off and manually set the time to BST then the times all work correctly (the only issue presumably being when DST is over at the end of the summer you will have to remember to manually set the time back an hour – but that’s a small price to pay for having the tide and current times right)

When using NauticPath charts
Here the problem was slightly more serious – whatever actual time and DST settings were used – these tide times always seemed to be advanced by an hour or so

Issue 3 – on certain dates 3HW + 1LW (or vice versa) are displayed
With Navionics charts

On odd dates the tidal time prediction (and the graph) appear to go awry and what is clearly a HW time is displayed against a LW text prompt.
e.g.
Milford Haven
Saturday, 19 August 2006

HW 3:24 14.4 ft
LW 9:48 8.3
HW 16:06 16.9
LW 16:42 16.7 (rather high for LW !)

Should be more like:
03:28 16.5ft
09:51 8.5ft
16:09 17.0ft
22:37 8.0ft

On other occasions (possibly when there are only 3 tides in a day) the graph can miss one of the red (or blue) sections

I would be grateful if you could acknowledge the receipt of this email and whether you can understand (and replicate) the issues raised. I’m happy to try and provide further examples if that would help.
I would also appreciate an estimated timescale within which I might expect fixes to these issues.

Issues 1 & 2 can be circumvented (if the user spots the problems and works out what to do – and is happy to work in feet) – Issue 3 appears to occur on odd days and currently just has to be spotted before relying on it.

I would urge you to fix these issues as soon as possible as they detract from what is otherwise a fine product – especially in the European market place.

Oh and one minor suggestion for the 3600 – as this does not use the Lowrance bus – would in not be a good idea to ship a dust cap for the socket to prevent water getting in if used on deck ? (Fortunately it appears to be the same connector as for many underwater flash housings – so I had a spare cap – but many would not).
 
I would have added - Please supply with a more manageable and softer cable to allow cable runs to be more easily made.
Particularly on the 3500C ..... they are stiff and awful cables.
 
Thank you for all your research on this! I'm sending an email to both as this and the crappy stiff connector cables are the only flaws in a fantastic and very cost effective piece of kit.

Have you emailed YBW editors on this as one article in a national sailing mag could put some real PR pressure on them.

S
 
No I haven't...I think this is one of the next steps. I'm also debating whether to alert Lowrance / Silva via. a copy of the forum posts, along with the number of viewings, and see if that gets their attention. It'll be interesting to see what reaction yourself and others get to your e-mails, and then maybe plan some joint action along these lines. Thoughts on that everybody, and timing? Let's all keep in touch on this anyway.
 
Re: Lowrance plotter tidal module bugs - Reply received

FWIW - have received a response to my email (see earlier in this thread)

Issue 1
Lowrance are working on this one, look out for next software version being released on their web site.

Issue 2
There may a fix for the Nauti Path - there has been an update on the tides file - please would advise the file dates on your card.

Issue 3
Please advise Navionics using http://www.navionics.com/DiscrepancyReports1_new.asp

I have now advised them of the dates on the card (21/02/2006) and reported the issue to Navionics as well
 
Re: Lowrance plotter tidal module bugs - Reply received

Well at least it seems they've listened to my rants over the last 9 months! Pity they didn't communicate anything back to me. However, for other users, don't let them off the hook. I still think we're getting a low priority on this (doesn't affect the American users)...so keep the e-mails going. Thanks for the feedback anway. Keep in touch, and let's all keep an eye on the Lowrance website for updates.

PS - just noticed that the link for the discrepency report is to Navionics! They're passing the buck. I'm convinced this is nothing to do with Navionics, but because Lowrance want to sell NauticPath charts, they will do very little if anything to fix this Navionics chart issue. So I was too kind to them...WE NEED TO KEEP THE PRESSURE ON.
 
In Navplanner using Navionics chart the tides for 19/8/06 are
3:29 5.0m
9:51 2.5m
16:15 5.2m
22:37 2.4m
Look pretty secure to me?
 
Thanks for that.

I've just emailed them again (including your figures) suggesting that the bug must therefore be in the Lowrance interpretation of the data rather than the Navionics data itself.

Looks like I'm going to end up having to buy the NavPlanner !

Thanks
James
 
Ref. Belfield ...

It actually has provision for more than 1 year ... mine runs fwd for a number of years .... its a 2004 version with data till 2006 end. A new serial number and it will add another 3 yrs ....
 
Response to my email num 3 (or was it 4 - think I must be reaching nuisance status /forums/images/graemlins/grin.gif) - after trying to palm me off with "it must be down to Navionics" - I just got from silva ltd:

"I am coming to the same conclusion after another customer is now reporting the same problem for the Solent.
I have asked for this issue to be taken up with Lowrance."

Someone else from the forum per chance /forums/images/graemlins/wink.gif - obviously takes 2 people to make it a bug !

In response to my email:

Issue 3:
As per my other email to you – I am now fairly sure that it is the Lowrance rather than the Navionics that is at fault – as the Navionics Gold charts appear to produce the correct tide times in their desktop software (when using exactly the same data).

The suspicion is that the Lowrance unit may be getting “confused” when there are only 3 HW/LW tides in a 24 hour period as opposed to the usual 4 – but I have to confess to have not spent the time on this to try and track it down exactly.
 
The irritating thing is that I demonstrated all this to Lowrance and Silva on their stand at the LBS in January, and spoke with Navionics on their stand. Silva have known about it since Sept.2005. Since then I've sent endless examples of suspect dates to Silva & Lowrance USA, who also said Navionics had been on the phone to them....yet months later it's like they've just heard about it /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif
 
Yes - I did point out that I was aware they had known about this since last Sept.

I won't hold my breath for a fix - when I asked about the likely arrival time of just the m/fathom issue which they do claim to already knwo about and can only be a trivial fix - the response was from silva that Lowrance don't generally let them know - it just arrives on the website.

I'm also aware that all the responses have come from Silva - who of course aren't actually capable of making any changes - they can only lean on Lowrance /forums/images/graemlins/mad.gif
 
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