Navionics - A Childrens Toy?

[Tillsbury]

Originally Posted by carstenb

seriously - once you leave Panama - ain't no internet until NZ or Australia (I have to say Nuku Hiva now has moderate speed internet - but most other places you can forget about it

And don’t plan on it everywhere either. I can sail six miles out of the second biggest city in NZ and there’s not a scrap of signal of any kind. I quite like it

Sailing down the coast of nz you’ll get 3G or 1G signal good enough for a phone call or text around 1/10th of the time. Very rare to find anything worth using for data. Satellite only most of the way.

Make sure your raster charts are up to date : free and updated at least monthly... Google Earth can be several years behind.

[Simi 60]

Originally Posted by Tillsbury

And don’t plan on it everywhere either. I can sail six miles out of the second biggest city in NZ and there’s not a scrap of signal of any kind. I quite like it

Sailing down the coast of nz you’ll get 3G or 1G signal good enough for a phone call or text around 1/10th of the time. Very rare to find anything worth using for data. Satellite only most of the way.

But that's why you do your planning before you go and get all the kap or mbtile that you need.

Make sure your raster charts are up to date : free and updated at least monthly

And you need a data connection for them as well and, there is no guarantee of 100% accuracy.

... Google Earth can be several years behind

.
Thankfully, rocks and reef don't grow that fast.

[Tillsbury]

Sometimes they do, that's where they come from. The seabed 100 miles north of here raised by up to 5 metres back in 2016... Made pilotage near the harbour very interesting

[conachair]

Originally Posted by Tillsbury

Make sure your raster charts are up to date : free and updated at least monthly... Google Earth can be several years behind.

More satellite images available than just Google, bing can be good as well, and the great thing is you are allowed to use the all and anything else you can get your hands on - at the same time!
Not much to be gained from updating raster or vector charts in a lot of the world,the chart data can be ancient. Luckily these days it's easy to check many sources against each other.

[arsenelupiga]

started preparing to sail to fiji and downloading 6 series of detailed satelite photos of the whole area, ie google, bing, nokia etc. Will be several GB and several days but have enough disk space and fast internet. Navionics apparently 99% correct so will look at it for reference but everything crosschecked against photos. There are large number of reefs, one misplaced is enough to ruin the trip.

Different types of electronic maps can be simply copied one from the other, so not really different source.

See Stary Horizons article about sas-planet to learn how to do use and download.

[Buzzman]

It's going to be interesting to see what 'apps' and other 'disruptors' pop up after Starlink launches globally.

Sat comms mid-Pacific, on a telco plan price, anyone..???

[Davo1404]

0

Originally Posted by arsenelupiga

started preparing to sail to fiji and downloading 6 series of detailed satelite photos of the whole area, ie google, bing, nokia etc. Will be several GB and several days but have enough disk space and fast internet. Navionics apparently 99% correct so will look at it for reference but everything crosschecked against photos. There are large number of reefs, one misplaced is enough to ruin the trip.

Different types of electronic maps can be simply copied one from the other, so not really different source.

See Stary Horizons article about sas-planet to learn how to do use and download.

The old saying for reef navigation still stands today even with lots of electronic resources.
'Only move between 10am & 2pm with the sun out". We religiously followed this while in Fiji waters.

[cortezsailor]

Really in the end trusting any device or expecting it to be even 90%, accurate is poor seamanship

[Simi 60]

Originally Posted by Davo1404

0The old saying for reef navigation still stands today even with lots of electronic resources.
'Only move between 10am & 2pm with the sun out". We religiously followed this while in Fiji waters.

So what happens when you need to travel more than 20nm?
Or weather conditions force you to move outside of those hours?
Do you send an email to the weather gods telling them to "hold off until a more suitable time of day and make sure its sunny as well thanks".

[carstenb]

Originally Posted by cortezsailor

Really in the end trusting any device or expecting it to be even 90%, accurate is poor seamanship

Perhaps, But when we are talking about century old harbors in a well-developed western country with an established chartograpy department - I'd expect the measurement to be spot on.'
Sure some silting or if the harbor has been dredged then some lag time before ti shows up on the charts.

The issue here is that C-ap, Max Sea and Navionics all get their data from NOAA. So they are using the same base data source.

C-Map and Maxsea manage to transfer this data correctly showing the harbor at 2.7 meters (confirmed by eyeball and talking with the harbormaster and several boaters with sailboats in their slips).

So the question is: Is Navionics incompetent or are they lazy or do they not do their work correctly.

Question 2 - is this a one-off instance or are their supposedly sailing charts of such poor quality as to be totally unreliable.

We've sailed almost 25,000nm using C.-Map and MaxSEa and so far found them quite accurate..

[rslifkin]

Originally Posted by carstenb

So the question is: Is Navionics incompetent or are they lazy or do they not do their work correctly.

Question 2 - is this a one-off instance or are their supposedly sailing charts of such poor quality as to be totally unreliable.

For the areas I've traveled in the Great Lakes and Long Island Sound (and areas in between), Navionics charts seem to match up to the NOAA charts pretty well and both are pretty close to reality. I found a few spots along the Erie Canal where the buoy positions differed slightly between the NOAA and Navionics charts, but that seemed to be down to recent buoy moves where one was updated before the other.

Based on things I've heard from others, it seems like some chart vendors have better coverage in some areas than others, but none are perfect everywhere. Personally, I tend to run with Navionics on the plotter and NOAA raster charts up on the laptop next to the helm. When I upgrade my electronics at some point and have an MFD setup that can handle more than 1 chart type at a time, I'll probably keep some C-map charts somewhere in the system as well.

[Simi 60]

NOAA only does a small part of the world.

[CassidyNZ]

Originally Posted by arsenelupiga

you are a lucky man.

Here is beauty for you from east coast australia. Underwater rock west of Great Keppel Island is 114m away on map from real position. We can only hope you keep your luck. Maybe get laptop and download all pics before going to travel ...

Just asking . . . . how far underwater is that rock? Can one sail over it! Is it marked on a normal chart?

Of real interest to me is whether all of these obstacles in the sea suddenly turned up since the introduction of electronic navigation wizardry or where they always there marked on charts and routinely avoided by shipping. Seems that the existence of Google Earth has made all the obstacles in the sea more dangerous than they have been for centuries and that those who choose not to use GE are placing their lives at risk.

As for being lucky, electronic wizardry has only been around for maybe 25 years and in its present form for a lot less than that and thousands of sailors (hundreds of thousands of ships) plied the oceans for an awfully long time before a Google Earth - did they all just get lucky? I don’t think so.

Yes I get the fact that Simi (and others) wants belts and braces, places all his faith in wizz-bang technology with multiple redundancy when it all goes tits-up and that’s cool but to suggest that sailors who choose a less technical path stay alive simply by getting lucky is a stretch.

No, I don’t have a laptop on board, no I don’t have OpenCPN, no I don’t have a wizz-bang chart plotter but I do take care in my planning and I do exercise good seamanship but I don’t depend on satellite pictures to keep me safe.

Call me old-fashioned . . . . . .

[requiem]

Originally Posted by CassidyNZ

Of real interest to me is whether all of these obstacles in the sea suddenly turned up since the introduction of electronic navigation wizardry or where they always there marked on charts and routinely avoided by shipping. Seems that the existence of Google Earth has made all the obstacles in the sea more dangerous than they have been for centuries and that those who choose not to use GE are placing their lives at risk.

As for being lucky, electronic wizardry has only been around for maybe 25 years and in its present form for a lot less than that and thousands of sailors (hundreds of thousands of ships) plied the oceans for an awfully long time before a Google Earth - did they all just get lucky? I don’t think so.

The IMO has a "History of Safety at Sea" page. When it gets to the parts on British regulations it mentions the Merchant shipping Act of 1850 and related legistration. It also notes: "However, these measures had little effect, and an average of two thousand ships were lost annually."

[El Pinguino]

Originally Posted by requiem

The IMO has a "History of Safety at Sea" page. When it gets to the parts on British regulations it mentions the Merchant shipping Act of 1850 and related legistration. It also notes: "However, these measures had little effect, and an average of two thousand ships were lost annually."

Two thousand ships lost annually..... golly... and all because they didn't use GE!!

But wait..there's more...

'This trend began in 1836 with the appointment of a Parliamentary Select Committee to examine the causes of the steady increase in shipwrecks. The investigation drew attention to ten determining factors, including defective construction, inadequate equipment, imperfect state of repair, improper and excessive loading, incompetence of masters. drunkenness among officers and crew, and marine insurance which inclined shipowners to disregard safety. A first aerie of measures was introduced after the publication of the parliamentary report. In 1839, restrictions were placed on the transport of timber deck cargoes in the North Atlantic. In 1840 appeared the first rules on lights and traffic at sea. From 1846, passenger ships had to be inspected by officially approved surveyors.'

No mention of running into terra in the first six causes listed....