Another Navionics Victim in Georgetown

[denverd0n]

Originally Posted by Pelagic

WOULD YOU RELY ON THOSE THIRD PARTY TRACKS.?...for a first time transit through a narrow safe passage?

Depends on what you mean by "rely." I most certainly would not just blindly believe that the track is safe, and I can blast through without concern. I might consider it, with someone at the bow, or up the mast, going slowly, in the proper sort of light, keeping a VERY close watch at all times.

[Thumbs Up]

Is this the thread to rag on Navionics? They have no MOB function on their app! It takes a total of 11 operations on the android app to mark your current location and set a course back to it. How is this acceptable?

[a64pilot]

Originally Posted by Dockhead

It's 50%, but your point is equally valid.


I agree with your analysis. Sloppy seamanship is the main reason people don't update their charts, but charging so much for updates is a big factor, I'm sure.



Another issue is how cruising areas are priced. Going back to the days when the old CF cards were very small, charts used to be sold for very small areas. These areas were gradually increased, but they are still way too small for long distance cruisers, and it seems to me they are kept artificially small just to exploit this. To cover the whole Baltic Sea, you need three (3!) Navionics cards costing more than £1000. That's just ridiculous. And if you try to get your charts from NV Charts, it's even worse.



Why should you pay 10x as much for cartography, just because you cover a larger area, in the same amount of time? Your usage of the product is not more intense, from one user intensively using a smaller area. You should be able to pay a reasonable price for a whole continent, at least -- perhaps on a subscription basis.


Cheap updates would be great, and I might even be willing to pay more for the original card, especially if it covers a really large area.


I also wouldn't necessarily be against a subscription system where you buy - for a reasonable price -- just one year of access to a given area, and you have to buy it again next year if you're going to be there again. I bought charts for OpenCPN of Faroes and Iceland like that, and I was pleased to have right up to date charts of those areas, for a reasonable price (less than £100 for both IIRC), and didn't mind that they disappeared in a year.

Not all chart suppliers are doing as you say, in fact C-map seems to be going the other direction in that they are supplying larger and larger maps coverage, for less money.
Now I’ll admit that the display isn’t as slick as Navionics and there are no Satellite photos of Marina’s etc., but the important Nav data is there, and in the Bahamas particularly, as it’s Explorer data, it’s the most accurate there is.
Follow this link, it is one chip that for US Sailors, both coasts, Great Loop etc., covers all the area that most will ever sail, for well less than $200.
https://www.thegpsstore.com/C-MAP-MA...ico-P3688.aspx

[Captain Bill]

When I first heard the mayday the sun was literally half way down over Great Exuma Island. With the sun angle that low and the inlet aligned so that the vessel was sailing right into the sunset I seriously doubt having anyone in the rigging would have helped.

Occasionally we hear people offering chart cards for sale or trade on the cruisers nets in the Bahamas and elsewhere. It's pretty clear that these are usually not the latest editions. That being said I am somewhat guilty of contributing to the issue, because a couple of years ago I gave an old Cmap NT+ card to a guy in a new lagoon 44 that had no detailed charts of the Bahamas with him at Conception Island. He only had the large scale charts that originally came with his chart/plotter. Was I wrong to help him avoid a Darwin award?

[cyan]

Originally Posted by Seriously Slow

Just a note, 7;00 pm is very close to sunset here in Georgetown. I do not think it would have been much better if crew was up the mast as he was traveling towards the west.

Exactly what I was thinking. The crew in the crow's nest and those polarized sunglasses are not helping much whilst motoring straight into the sunset.

[Pelagic]

Originally Posted by denverd0n

Depends on what you mean by "rely." I most certainly would not just blindly believe that the track is safe, and I can blast through without concern. I might consider it, with someone at the bow, or up the mast, going slowly, in the proper sort of light, keeping a VERY close watch at all times.

What I mean are the anchorage locations and access tracks to and from that anchorage, provided by another cruiser who has already been there.

Would you rely on that to make your First slow approach to an anchorage in less than ideal visual conditions?

I am just wondering how much these shared "safe" navigational plots", created and networked by cruisers are used and relied upon?

[a64pilot]

I can see maybe being sure that you have the latest greatest charts for aircraft, if your shooting an IFR approach, it’s required.

However not that much really changes in the Marine world and I’d suspect it’s been a long time since anyone has surveyed the waters the Bahamas.

I’d be interested to know how old the Explorer database is for example, I bet it’s older than many of us think.

[a64pilot]

Originally Posted by Pelagic

What I mean are the anchorage locations and access tracks to and from that anchorage, provided by another cruiser who has already been there.

Would you rely on that to make your First slow approach to an anchorage in less than ideal visual conditions?

I am just wondering how much these shared "safe" navigational plots", created and networked by cruisers are used and relied upon?

I have issues with Navionics sonar charts, which is what I think you may be referring to.
My issue is depth offset, I have a 3.8’ offset so that my depth displayed is my keels depth, when I see 0, we are about to bump.
The next guy displays real depth if you will, they know what they draw and know when they see that, they are about to bump.
We both report to Navionics our tracks, but are reporting completely different depths.
I’ve seen Sonar charts be way off, but consistently off, and assume maybe this is why and or how.
So, just me, but yes I’d use it, I wouldn’t trust it, but I use everything available to assist in what we used to call in flying situational awareness, the more sources of data you have to compare against each other, the better.

I’ve only seen one chart I’d trust in the Bahamas, straight up Explorer charts are the best, but I’m certain that Garmin uses Explorer data, and of course C-map says right on it that it’s Explorer data.
So I guess I’m saying that only Explorer data is from what I’ve seen, reliable, although there are a few ways to get Explorer data

[bcn]

Originally Posted by a64pilot

I’ve only seen one chart I’d trust in the Bahamas, straight up Explorer charts are the best, but I’m certain that Garmin uses Explorer data, and of course C-map says right on it that it’s Explorer data.
So I guess I’m saying that only Explorer data is from what I’ve seen, reliable, although there are a few ways to get Explorer data

Garmin has dropped Explorer Charts for Bahamas .
Has been discussed here and Explorer noticed some weeks ago:
https://explorercharts.com/chatter/b...-availability/

[Tillsbury]

Originally Posted by Jim Cate

Not familiar with the area, but NONE of those charts would encourage me to attempt to pass between those cays. Only an observer in the rigging and good lighting would suffice.

There may well be a good passage there, but none of those charts show such.

Jim

I’m with you there Jim, I wouldn’t want to go inside the 5m contour if all I had were those charts...

[Pelagic]

[QUOTE=a64pilot;2876138]I have issues with Navionics sonar charts, which is what I think you may be referring to.
My issue is depth offset, I have a 3.8’ offset so that my depth displayed is my keels depth, when I see 0, we are about to bump.
/QUOTE]

My thoughts are more general than that and akin to Jim's.
The ONLY electronic track I would follow in poor visibility conditions..... is one that I have layed down earlier and saved myself during optimum vis conditions.

Yes, I would use imported tracks as a guideline on First Transit, but not rely on them during low light conditions.

Chart Updates are a good thing, but really a red herring

Staying true to conservative seamanship decisions on when to stand off and wait for good visibility on first transit is far more important.

Do not be tempted by ECS magic !

[Dockhead]

Originally Posted by a64pilot

I can see maybe being sure that you have the latest greatest charts for aircraft, if your shooting an IFR approach, it’s required.

However not that much really changes in the Marine world and I’d suspect it’s been a long time since anyone has surveyed the waters the Bahamas.

I’d be interested to know how old the Explorer database is for example, I bet it’s older than many of us think.

Updated charts incorporate all of the cumulative Notices to Mariners. So new surveys is not the only reason to keep your charts updated. So this means corrected errors, new hazards, changed buoyage, shifted channels, reconfigured harbours, new no-go zones, etc etc etc etc etc.


It is really not true that "not much changes in the marine world" and I don't see how it's less important to have up to date charts on a boat, than it is on a plane.

[StuM]

Originally Posted by Dockhead

Updated charts incorporate all of the cumulative Notices to Mariners. So new surveys is not the only reason to keep your charts updated. So this means corrected errors, new hazards, changed buoyage, shifted channels, reconfigured harbours, new no-go zones, etc etc etc etc etc.


It is really not true that "not much changes in the marine world" and I don't see how it's less important to have up to date charts on a boat, than it is on a plane.

As an example, see the latest fortnightly Australian NOTAM publication. Note that these 48 notices are just the ones issued in the previous two weeks.


http://www.hydro.gov.au/n2m/2019/edi...2-416_2019.pdf

[IslandHopper]

Originally Posted by StuM

As an example, see the latest fortnightly Australian NOTAM publication. Note that these 48 notices are just the ones issued in the previous two weeks.


http://www.hydro.gov.au/n2m/2019/edi...2-416_2019.pdf

Chart corrections now theirs a novel idea, can't see it catching on though

[Captain Bill]

Originally Posted by Dockhead

Updated charts incorporate all of the cumulative Notices to Mariners. So new surveys is not the only reason to keep your charts updated. So this means corrected errors, new hazards, changed buoyage, shifted channels, reconfigured harbours, new no-go zones, etc etc etc etc etc.


It is really not true that "not much changes in the marine world" and I don't see how it's less important to have up to date charts on a boat, than it is on a plane.

This wouldn't have helped in the Bahamas, as there are no official charts produced here and no such thing as a Notice to Mariners. The old British admiralty charts are the closest things to anything official. Even the Explorer chart data is only updated once or twice a year by those companies contracting to distribute it. If the captain had at least recent charts he would not have been following the route he did.