Raymarine Plotter and Tide Graphs.

[mattnj]

I have an E80 plotter with an out of date (2005) navionics chart in there, does anyone have a similar plotter (c70, c80, c120, e120) with newer, updated charts and does it show tide information, mainly tide graphs?

I had a Navman that did, see attached, but cant work out if i get a similar feature on the raymarine somehow, and if my charts are just too old, does it have that feature?

I am on the latest firmware by the way.

 

[haydude]

I have a C80 and it does display tidal information, although the software is rubbish compared to a cheap Cobra I had on a different boat.

1) Ensure that you have the latest firmware, it can be downloaded from Raymarine's site upon registration and installed after copying it on a memory card (do not use the chart card)
2) The chart card MUST support specifically tide data. Older ones might not.

 

[AIDY]

check what version software your plotter is running... only newer software version's can pick tidal data up and animate it.... for C series you need 4.26 or newer... think latest is 4.29... E series is up to about 5. ???? sumfink.

you can download the latest version from the raymarine website.

once you have the latest software find a tidal diamond on the chart with a letter T in it and select it... you then can choose the tidal data as you picture above... or animate the tidal flow on the chart

 

[mattnj]

thanks....i did say in the post i was on the lastest firmware.....

Was really checking it did the sinewave type graphs, as per the navman picture, if i update my charts to the newer ones....does it?

 

[Ian_Edwards]

E series

We have an E80 with an up to date UK chart, and more or less up to date firmware (as of March this year and I haven't checked recently).
If you are at the top level of the menu system, with the cursor on a blank bit of the chart, press OK, the bottom left soft key should say "find nearest", press it and a list of options appear. Select the tide one and soft key should say "find". Press the key and you get a list of tidal station. Select the one you want and then you get a soft key option to show the tidal graph. I'm not on the boat just now, that from memory .... but it's about right.
I use it regularly, especially when anchoring, to make sure we have enough water under the keel at low water.
Hope this helps.

 

[Kelpie]

I've been meaning to ask a rather dumb question for a while and this thread may have answered it:
Where does my plotter gets its tide information from? And, following that, how reliable should I consider it? Especially when using the graph to calculate depth for getting over bars etc.
My plotter is a small handheld Raymarine which came with the boat, with no manual.

 

[Ian_Edwards]

Harmonic constants

No such thing as a dumb question!

The Proudman Oceanographic Laboratory, www.pol.ac.uk/, calculates harmonic constants for the Admiralty for standard ports and most plotter/navigator uses this method to calculate the tidal info’ based on the constants of that port and the time and date i.e. were the sun and moon are, that's also why you get sun rise and sunset info'.

The way I think of it is, it’s like adding a series of sine waves together of different periods (harmonics) and applying a different set of multipliers (constants) to each sine wave which are specific to each port. The resultant curve is the tidal height plot.

You can buy the harmonic constants and plug them into your own software, that’s what I think Raymarine and the like do. Proudman will also calculate you a set of harmonic constants for more of less any tidal location, for a price. I’ve done this when working on North Sea projects which were critical on tidal height.

My experience, and I have checked the calc' using a tidal gauges, is that they are very good, but they can't know about storm surges, high and low atmospheric pressure or flood water from rivers.

Hope this helps

 

[Kelpie]

Thanks very much! So, can I assume that the tide information will just keep on coming, then? I won't be approaching a bar one night to find that the plotter needs updated.... perish the thought! Of course I'd always get a second source of info but I must admit the plotter is incredibly handy.

 

[Ian_Edwards]

The answer is 19 years

The tidal cycle repeats after approximately 19 years, but you would expect the accuracy to gradually get worse over time. There is the effect of seawater levels rising because of the melting of the ice caps and the geological effects of plate tectonics, the south east of England is sinking by about 2mm a year, the north west of Scotland is rising by about 1.5mm per year. There are also local effects caused by new breakwaters, dredging/silting and tidal barrages should they ever be built. But in general all these effects are small and are masked by storm surges, high/low atmospheric pressure and the runoff from rivers and won't affect the average recreational sailor.
Hope this helps