Navionics tidal diamond phase error north France.

[jonjo]

Last Wednesday at about 17:00 I was heading NE up the Alderney Race with SOG peaking at 11 kts assisted by 6kts of tide up my tail. Since I am back home I don't have access to my navigation references but here is the interesting bit. From memory the tidal diamonds in the Race showed slack water around 9pm but just a few miles away the first two diamonds offshore north of the Contentin peninsular showed slack water around 6pm with an adverse ebb tidal flow following.

I carried on towards Cherbourg and plainly had the tidal current with me all the way to our 9pm entrance into the outer harbour.

The electronic chart was a brand new XL9 whole of British Isles.

My plotter is a handheld Raymarine RC400. Something must be wrong with the digital tide tables embedded within the chart or the plotter software, should I raise this with Raymarine or Navionics?

 

[D3B]

I have no tides available for my home port of Lowestoft on my card.

and i only got it updated 2 weeks /forums/images/graemlins/mad.gif /forums/images/graemlins/mad.gif

a return will be in order.

 

[Sinbad2222]

Oh dear that's bad news. I recently sold a boat with a Raymarine 435 plus Navionics XL3 card and the tidal information around the Solent was accurate. Maybe the XL9 "improvement" isn't an improvement after all which worries me as I am still trying to decide which plotter and cartography to choose for the new boat. I tried a Lowrance plotter with XL3 and the tidal information was total rubbish - I would never consider a Lowrance chartplotter again for this reason. I wonder if good old Garmin are best as is usually the case. Please keep us posted on how you get on with Raymarine and Navionics. Their attitude will be of interest - Lowrance couldn't care less although to be fair I have heard that they recently sacked their UK distributer, Silva, which may be significant.

 

[achwilan]

Welcome in the wonderful world of electronic navigation /forums/images/graemlins/laugh.gif

 

[Guest]

[ QUOTE ]
Oh dear that's bad news. I recently sold a boat with a Raymarine 435 plus Navionics XL3 card and the tidal information around the Solent was accurate. Maybe the XL9 "improvement" isn't an improvement after all which worries me as I am still trying to decide which plotter and cartography to choose for the new boat. I tried a Lowrance plotter with XL3 and the tidal information was total rubbish - I would never consider a Lowrance chartplotter again for this reason. I wonder if good old Garmin are best as is usually the case. Please keep us posted on how you get on with Raymarine and Navionics. Their attitude will be of interest - Lowrance couldn't care less although to be fair I have heard that they recently sacked their UK distributer, Silva, which may be significant.

[/ QUOTE ]

I thought Silva bought Lowrance .... maybe its a person that was sacked - not a company ?

The tidal error on Lowrance has been an issue for some time ... I wouldn't say that Lowrance don't care - they have been slow to find the answer and it's possible its a general problem with navionics as well .........

I like my Lowrance and to be honest the tidal bit is not used so much as a good set of tables ...

 

[Sinbad2222]

Silva started off in the dim and distant past as a compass manufacturer. They are now effectively wholesalers.
Navico, with headquarters located in Oslo, Norway,own B&G, Eagle, Lowrance, Navman, Northstar and Simrad.
Sailing a small, slow yacht round the Solent I found the tidal diamonds with speed and direction indication absolutely invaluable and far superior to tide tables. I would never need a plotter to navigate in the Solent but the tidal information was far more use to me. Apart from that if a manufacturer says his product does something I expect it to do it. I think you must be suffering from the British characteristic of expecting nothing and accepting anything, an attitude which led to the collapse of our manufacturing industry!

 

[jonjo]

[ QUOTE ]
I would never need a plotter to navigate in the Solent but the tidal information was far more use to me.

[/ QUOTE ]
Same here, I make frequent use of the tidal height and current data on the electronic charts which is why I was spooked to find a manifest error. I cannot remember the last time I looked at a printed tide table on board.

The RC400 is not a practical pocket device but it is small enough to hold while sitting anywhere doing passage planning for the next day.

 

[Guest]

No in fact I am one of the guys who was ranting at Lowrance Tech to sort it ... and to Silva .... I even have personal contacts in both camps over it ...

My reason for sticking with the Lowrance is that price for price and general performance it is better IMHO than nearest competitors ... and generally on par with more expensive stuff. The fact that one aspect of its use is suspect - please tell me one modern bit of kit that doesn't have a fault of some description ? Ok - I can pay 50% again on top and get a tidal data window that I rarely use ... in fact I only used it to check others complaints about it !!

As to Silva / Lowrance ... I'll not be drawn ... /forums/images/graemlins/wink.gif

 

[Guest]

[ QUOTE ]
[ QUOTE ]
I would never need a plotter to navigate in the Solent but the tidal information was far more use to me.

[/ QUOTE ]
Same here, I make frequent use of the tidal height and current data on the electronic charts which is why I was spooked to find a manifest error. I cannot remember the last time I looked at a printed tide table on board.

The RC400 is not a practical pocket device but it is small enough to hold while sitting anywhere doing passage planning for the next day.

[/ QUOTE ]

My plotter plots ... my PDA pda's and gives me tide via Belfields data program. I also have a Plam with Ptide ... Ctide on - so will always have tide data at hand somewhere ...

I can even call up scanned current charts for tide referenced times on my PDA with built in GPS - it plots me in the currents .. so I have direct reference ... a matter that Plotters no matter how good will not match. <y Lowrance 3500C has good current arrows ... but as with most plotters few and far bewteen ... ny PDA is much better at it ...

Sorry - no argument for me ... /forums/images/graemlins/grin.gif

 

[blup]

As a matter of interest, were these tidal (T) diamonds or the current (C) diamonds? I have the navionics platinum and have had longstanding and ongoing issues with accuracy. Whilst the latest version seems to have addressed the tidal diamond issues many of the current diamonds still remain inaccurate both in terms of the name and tidal information. Needless to say, discussions with Navionics continue!

 

[jonjo]

I did not check any <T> diamonds. The <C> ones I referred to are about 5 miles offshore from the French coast, the first one is north of Cap de la Hague and the second is the next one east at the same latitude.