Raster or Vector charts - which to choose and use?

Robert Wilson

Robert Wilson

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I wonder which of the two is the most reliable/useful/popular?
I know the basic differences between the two but have no operating experience of either.

I am about to go for one or the other to download to my tablet (ASUS), but reading PBO this month I am in a quandry.
Ideally I would like to have a tide facility, SOG, COG, easy input of waypoints and courses etc and as much "sensible" detail as realistically possible on the charts; also and knowing that the chart/download is not going to be obsolete within a few weeks/months or even years.

PBO seem to be keen on Navionics, but I've heard/seen a few grumbles about lack of support and longevity.
Memory Map sounds good but it's raster and I get the impression that vector is more practical.

Help me, oh wise ones, please.
Ta
 
I used to use navionics and liked the vector charts. Now I use MX mariner with raster charts. Mostly because the details of the shore etc are clearer.

Whoever did the navionics charts obviously doesn't have English as a first language so most of the shore details are random things like 'deciduous tree' and other nonsense.

If you're world cruising is go for vector charts like cm93 or the newer ones that I can't remember the name of.
 
Every chart goes out of date as soon as it's printed / saved. I still use charts that are 20 years old but take certain things into account when using them.

On board i use both raster and vector charts. The plotter at the helm has C-Map on a SH300 but I also have MM on the iPad for planning, daydreaming etc.. Raster charts will I think gradually disappear as more people get use to vector charts as opposed to us oldies that grew up with Admiralty charts and their familiar look.

At £40 for Novionics and £30 for MM, I'd get both. :)
 
I use MM on Android and PC and Navionics on Android. If I could only have one on board it would be Navionics for the tides & current info and the seemless, scalable chart, though MM is a better planning tool. I have had support issues with MM so I wouldn't dismiss Navionics on that basis alone.
 
I use Vector.
With Raster, what you see is what you get at any level of zoom on that particular chart
If zooming in switches to a larger scale chart then you will get the level of detail on that chart.
Vector will hide some details till you zoom in, then they appear.
Some / most / all Chart Plotters (I can only speak of Standard Horizon) have a facility (on SH called Flex zoom) which holds the detail shown on the screen when you zoom (normally out)
 
Quiddle said:
I use MM on Android and PC and Navionics on Android. If I could only have one on board it would be Navionics for the tides & current info and the seemless, scalable chart, though MM is a better planning tool. I have had support issues with MM so I wouldn't dismiss Navionics on that basis alone.
Click to expand...

That's interesting. In what way better? And what planning features does Navionics have?
It's not as if I'd be crossing the Bay of Biscay or navigating the fjords of Norway - well, not yet a while!

Vector seems to be more useful for myself for coastal work?
 
There is a theoretical down-side to raster in that narrow lines or small symbols can disappear when zoomed out. This is not related to the importance of said line or symbol, but purely to its representation in the raster image. Vector databases will not do this, except in a properly controlled cartographically sensible manner. Vector charts can be sensibly generalized at smaller zoom scales than the original, and customized for different displays; raster charts can't. Vector charts can have ancillary information attached to features; raster charts can't.

Basically, there is no down side to vector, and lots of potential negatives to raster.

Raster is a derived product anyway; all charts are produced from vector databases these days (unless it's a VERY old chart!).
 
Thanks, one and all, particularly #7. It looks like I'll be going for vector charts, most likely the Navionics being recommended, and I have a file of it on my desktop which I seem to get on OK with.

Is there anywhere these "apps" can be tried before buying, just to make sure the best for oneself has been chosen?
 
Might be worth reading the info provided with the Antares charts as presumably you will be using them with your package so the ones that Antares recommends and integrates them best would be at the top of my list.

Edit: you will have probably read about it but there has been quite a lot of criticism of Navionics not keeping up with the Android releases. I see you mentioned longevity in your original post but I remember a year or so ago when Google released a new Android version and then many people were left with non functioning charting. This was rectified but there was a considerable delay. You could of course prevent your tablet from downloading new versions and if it is an oldish one that will probably be satisfactory.
 
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AntarcticPilot said:
Basically, there is no down side to vector, and lots of potential negatives to raster.
Click to expand...

There may not be in theory, but in practice I find the zoom levels at which things are hidden or displayed on my plotter infuriating. Really quite substantial buoys are omitted when you look at a whole area, and when you zoom in enough to see them you can't tell which area you're looking at. My master plan for Ariam's nav arrangements assumed that I would use the plotter almost exclusively in coastal waters, only putting a paper chart on the table for Channel crossings and similar longer legs. In practice I've found that I still need to have a chart out to understand what's around me, then I can use the plotter to keep track of where I am within the known area. If I didn't have the paper charts, I would probably use the (raster) Imray chart app on my iPad in a similar manner.

Pete
 
prv said:
There may not be in theory, but in practice I find the zoom levels at which things are hidden or displayed on my plotter infuriating. Really quite substantial buoys are omitted when you look at a whole area, and when you zoom in enough to see them you can't tell which area you're looking at. My master plan for Ariam's nav arrangements assumed that I would use the plotter almost exclusively in coastal waters, only putting a paper chart on the table for Channel crossings and similar longer legs. In practice I've found that I still need to have a chart out to understand what's around me, then I can use the plotter to keep track of where I am within the known area. If I didn't have the paper charts, I would probably use the (raster) Imray chart app on my iPad in a similar manner.

Pete
Click to expand...

With vector you (or the software you're using) is completely in charge of what is displayed at any particular zoom scale. With raster, it is possible when zoomed out for features to become invisible in manners entirely dependent on the vagaries of the display, the exact pan location and the zoom factor. On a raster chart, it is very easy for a line which runs east-west to be visible, but one which runs NW-SE to be invisible; ot a line which should be solid to be displayed as a broken line.

In other words, with vector you have control; with raster you can have changes in display that you don't control and which are unpredictable. Further, raster does not allow useful functions such as removing unecessary information - for example, where I sail, information for ships about port limits and navigation channels is clutter to a yacht, and is easily removed from the display. This is not possible with raster data.

Of course, you should never zoom in substantially beyond the designed display scale of the chart; the problems I refer to are when you are zoomed out. Most raster software avoids the worst problems by automatically changing the chart selected for display at different zoom levels, but there is always a point beyond which there is no larger or smaller scale chart available.

Although I've been in digital mapping since 1979, I also carry paper charts as well as electronic ones. Paper and electronic representations do different things, and of course provide a backup with no shared mode of failure.
 
Taking all into account, and assuming my ASUS Android can take it, I'll be going for vector, prob Navionics, but as suggested, I may get the Memory Map as well; I already use it for land based walking/driving etc, but also find it a useful and quick map to gauge distances on the water when "day planning".

Many thanks one and all. Keep it coming, it's useful response to my questions and I'm sure there's more out there.:)
 
Does Navionics have tidal data built in ?

Returning to the original post our main plotter uses Garmin bluecharts which are vector based. You can change the level of detail at each level of zoom (I think) but sometimes key nav marks dissapear at the level of zoom I often use. Sometimes I manually enter a mark at important points which are always shown at any level of zoom. Maybe Navionics could do this also as a workaround.
 
Robert Wilson said:
Is there anywhere these "apps" can be tried before buying, just to make sure the best for oneself has been chosen?
Click to expand...

Although the Apps and iBooks are for iPad only you can get some idea of what you can expect on screen on your own tablet by going to routelist.co.uk and sampling some of the screen shots and sequences on the website. Marine Imray Charts is a raster scan and Navionics, Garmin and MaxSea are vector scans. Shame you don't have an iPad otherwise you could download sample chapters of each book free.

Regards Chris M.
 
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