Lagoon 450 (Next Life) damaged in the Exuma, The Bahamas

[Kettlewell]

Lease on life--who is that chart from?

[Lagoon4us]

Originally Posted by LeaseOnLife

Right on. A bit further down the line it says "Range 6, Worlds end Reef".

Probably taken from a Don Street guide:

LMAO they are lay/reference lines the giveaway is they lay point to point, so where are they referenced as routes? ....

[LeaseOnLife]

Originally Posted by Kettlewell

Lease on life--who is that chart from?

sorry, forgot to add: cmap

[Cotemar]

Originally Posted by Kettlewell

Here's the raster chart of the Cuttyhunk entrance channel and a screenshot from the Navionics website. That little bit of submerged jetty extending out from land towards the C9 buoy is completely underwater at high tide and people in shallow draft boats try to cut through there. It's not a serious problem for deeper boats, but I think it is interesting that it disappears on some vector charts--don't have any at hand at the moment, but it doesn't show up on the Navionics web map accessible from their home page, and I've noticed it missing from other vector charts. I wonder what else is missing?

Every chart I bring up shows that submerged jetty extending out from land towards the C9 buoy, except Navionics.

Click on photos to see detail

[Sand crab]

Originally Posted by rourkeh

There is an identical boat, brand new, that was run aground in the BVI a few months ago and had the bottom ripped out of both hulls from the bows all the way back to about 3/4 of the way to the stern. If you could see the exposed fiberglass work you would never get on one of these boats again. You can read the newspaper through the glass, and there are voids in the layup, with dry spots everywhere. The owner ran the boat up on the rocks and it was pounded to death and sank. They floated it and brought the salvaged vessel back to Nanny Cay Marina.

This thread developed as a spinoff from my other thread.
http://www.cruisersforum.com/forums/...50k-94833.html

[LeaseOnLife]

Originally Posted by Cotemar

Every chart I bring up shows that submerged jetty extending out from land towards the C9 buoy, except Navionics.

Click on photos to see detail

On the iphone/ipad version from Navionics it does show some obstruction in the user added layer.

[Lagoon4us]

In no defence towards Navionic's but isn't that detail of little importance it's on the land side of the bouy but not in navigable water, unless once again corners are cut?

[tartansail]

Originally Posted by Cotemar

Every chart I bring up shows that submerged jetty extending out from land towards the C9 buoy, except Navionics.

Click on photos to see detail

Interesting that, on the other hand, there is depth marker just east of that submerged jetty in the dark blue that is listed at 5/9 on OpenCPN and Garmin and 6 on the raster chart. I hit a rock with my rudder in 2011 right over those depth markers that I estimated at 4 feet since my rudder draws just under 5'. I reported it to NOAA in 2011(with guidance from another CF'er). Navionics shows 2/7 and a rock. Believe it.

[Cotemar]

Originally Posted by Lagoon4us

In no defence towards Navionic's but isn't that detail of little importance it's on the land side of the bouy but not in navigable water, unless once again corners are cut?

Absolutely, but at this point it’s just about chart accuracy. Everyone has the microscope out now.

[Lagoon4us]

Pacific would/will be interesting....

[Cotemar]

Originally Posted by tartansail

Interesting that, on the other hand, there is depth marker just east of that submerged jetty in the dark blue that is listed at 5/9 on OpenCPN and Garmin and 6 on the raster chart. I hit a rock with my rudder in 2011 right over those depth markers that I estimated at 4 feet since my rudder draws just under 5'. I reported it to NOAA in 2011(with guidance from another CF'er). Navionics shows 2/7 and a rock. Believe it.

That Navionics chart is in Meters,
The 2.7 meters = 8.8 feet

[ka4wja]

I have read this entire thread, as of when I starting to type this, up thru the last post (#184)....

1) First off, I wish to say how sorry I am to read of Rolf's tragic experience, but am glad to know that everyone is okay....


2) Next, I'd like to thank Bob Stewart for his excellent posting!!!!
I myself, grew up sailing in the Bahamas (first long-term cruise thru the Exumas was in 1965) and while I've made a living in the commercial electronics industry (and have Navionics Platinum charts in my E-120 and E-80 plotters), I still use the old venerable "Yachtsman's Guide to the Bahamas", US DMA/NGA charts, and especially my eyeballs!!! .....and yes, now (just bought 'em 2 - 3 years ago) I also have the "Explorers Charts", and Steve Pavilidis' guides....(but still prefer my favorite, "Yachtsman's Guide" and US NGA Charts....)
Whatever you wish to say about how "old fashioned" my approach is, I can tell you that the old fashioned "Yachtsman's Guide to the Bahamas" is
tops in my opinion!!!

Originally Posted by W32PAMELA

Attachment 54855
DMA chart 26286 c 1995
Attachment 54856
Explorer charts c 2000
Attachment 54857
Yachtsman's Guide to the Bahamas. The way it was done pre-computer.

The Bahamas is one of those places that everyone should have a guide book for. Pavilidis' guides, the Yachtsmans Guide or the Explorer chart books will work well. Every pass commonly considered usable will be presented with a verbal description. The description should be read before attempting the pass for the first time. Anything not discussed should be considered unusable or if you are adventuress should be explored by dinghy first.

Attachment 54860
This is the Explorer chart raster version of the Eastern entrance. While they show straight line between way points everything needs to be done visually between waypoints. There should be no following of magenta lines or waypoints in the Bahamas without a careful visual watch. The route that was clear last month may have a sunk Haitian boat, Mail boat or airplane on it this month.

3) I suspect that for many here, the most important part of this post is:
My Navionics Charts (Navionics Platinum, circa 2006) do NOT show ANY passage between Guana Cay and Fowl Cay at all!!!
There are rocks and shoals....
There is NO magenta line, NOR recommended track/route!!!!
(perhaps there are differences between the Navionics "chartography" when it was "configured for use" as PC navigation software and/or when it set up for a iPad/tablet "App"????)

a) On my Navionics Platinum chart (circa 2006), there are numerous rocks and underwater obstructions, prominently noted there on the chart, between Guana Cay and Fowl Cay....(3 to 4 shown across the eastern end of this "pass"/"cut", and 4 across the middle and western end)
But, just as important, there are shallow soundings (3' - 7') between these charted obstructions and throughout this area out a couple hundred yards....and shoals / 0' depths (that's zero feet depths) extending 50 - 75 yards out into this "cut" from the northern edge of Fowl Cay....
The entire gap between Guana Cay and Fowl Cay is only 250 yards wide, and NOWHERE on my Navionics Platinum Chart is there any semblance of a "pass" or "channel" between these two islands....
NONE at all!!!


b) My Navionics Platinum Charts (circa 2006) for SE US and Bahamas (running on my Raymarine E-120 and E-80 plotters), has NO magenta line (dashed or otherwise)!!!


c) There is NO line at all, leading to or passing thru this gap ("cut")between Guana Cay and Fowl Cay!


d) There is a solid black line, which is described correctly as a "bearing line", to/from the northern edge of Fowl Cay....heading NE'erly 1/2mi to 1 mi.....
This line, like other "bearing lines" on the charts, can be identified by placing the cursor on the line and pressing "OK", and a description and bearing details will show in a pop-up box on the screen of the plotter....
The description/details for this specific line show it as a bearing line, 240*M, distance 0.5nm....
(and this line, like other bearing/range lines on the chart, can be "turned off" / removed from the display by selecting "de-clutter", should these lines prove to be a nuisance to you....)

This bearing line, along with other bearing lines and "eyeball navigation", should allow you to navigate around the shoals/rocks/reefs and find your way into a "channel", such as Welk Cay Harbor / "alternative east entrance"....
But, again, there is NO such "cut" or "channel" between Guana Cay and Fowl Cay on my 2006 Navionics Charts ....
Not on my 2006 Navionics Platinum Charts...
Not on my "Yachtsman's Guide to the Bahamas" sketch chart...
Not on my Explorer's Charts, nor on my US NGA charts....

(although, from what some have posted here, it does appear that Navionics placed a "dashed line" thru the gap between Guana Cay and Fowl cay, on their "Navionics pc navigation software" and/or on their "Navionics iPad/Tablet App"......
Those that have posted this "dashed line" or "magenta line", please confirm that this IS where this you are getting/using Navionics Charts, as this is not the case on the 2006 Navionics Platinum Charts on my Raymarine plotters???)


e) I cannot show a "screen shot" since these charts are on my Raymarine plotter, but I think I'm giving a very detailed description (above) of this area, and now (below) of this solid black bearing line....

This solid black "bearing line" runs ENE'erly from the North edge of Fowl Cay ( GPS position 23* 29.825' N x 75* 42.345' W) to a position approx. 1/2 mile to the ENE (GPS position 23* 30.15' N x 75* 41.9' W), and is used as a "bearing line" (240*M and 0.5nm dist), along with another bearing line from the NE end of Man of War Cay, for your turn to the SSE for use of the Welk Cay Harbor Cut ("alternative east entrance to Elizabeth Harbor")...
These bearing lines allow you to come in from deep water, and turn into and pass thru the Welk Cay Cut (assuming you have visibility to take compass bearings), and keep you off the rocks/coral/shoals East of Fowl Cay and NW of Welk Cay....
While the surveyed lat/lon positions of the islands and associated shoals/rocks, etc. might never match their GPS positions (hence many complain "the charts are wrong"), unless the islands themselves are washed away these "bearings" (along with your "eyeball navigation", of course) are a possible way to navigate around suspect shoals and/or thru cuts....

On the Navionics Platinum Charts, this specific "bearing line" actually starts 1/2 mile further out (at GPS position 29* 30.402' N x 75* 41.554' W), about 1 mile ENE of the North end of Fowl Cay, in water depths of about 50' and is marked on the Navionics Platinum Chart as simply "waypoint".....with further Navionics Chart text along these bearing lines reading, "eastern channel" and "welk cay cut"....(and description/details brought up showing 240*M and 1.0nm dist)....
This should give you a reasonable point to sail to, and when approaching this point ("waypoint") use depth sounder and eyeball navigation.....and, especially if you have cloudy skies or are heading into the sun, use these bearing lines to navigate into Welk Cay Harbor Cut...

So, while I personally would NEVER recommend cruising the Bahamas without use of "eyeball navigation", nor without the "gold standard" of guides ("Yachtsman's Guide to the Bahamas") and up-to-date paper charts......as far as I can see the 2006 Navionics Platinum charts DO have the shoals between Guana Cay and Fowl Cay marked correctly, do NOT show a pass/cut where there isn't any, and DO show bearing lines to island end points and prominent land features, so you could use these charts, and the depths / bearing lines shown, to navigate into Welk Cay Cut.....
BUT....
But, I see others here posting "Navionics Charts" that showed magenta lines going up to the middle of the gap between Guana Cay and Fowl Cay, and some posting "Navionics Charts" showing this line running thru this gap, implying that it is a "cut" / "passage".....and some have mentioned that this is shown as a "recommended track" on these Navionics Charts.....
So, I'm assuming that there ARE vast differences between the chartography of various "Navionics Charts" and/or the software implemented for use on pc's and/or Ipad's/Tablets????

I do hope someone (Navionics???) could clarify this....Please!!!
Perhaps Giuseppe Carnevali would be so kind as to clarify these issues????


f) As I sit here and look over all of this, my mind is reeling with the thought that some "software guy" or "proof reader" saw a thin black line on the chart (the useful bearing line) and saw it leading from a waypoint to the end of an island (as a bearing line should), and thought that it should pass between the islands, and so he simply moved the line or re-drew the line!!!!

While this seems unconscionable (and outrageous) on the surface, and as such almost an impossibility, I'm left wondering if this is in fact simply what actually happened???

Using my newly gained knowledge from this thread, that it appears changes to "Navionics Charts" on-line (for PC navigation and/or iPad/Tablet Apps) can be made instantly (and frighteningly without ANY professional/certified survey!!!!), so the assumption that "someone" at Navionics simply "moved the line" or "re-drew the line" (and either changed its color, or the software automatically changed the line's color???), and hence at least implied that there was a "pass" / "cut" between Guana Cay and Fowl Cay, seems quite plausible to me....
And, is it possible that Navionics went even further, and denoted this "newly created" or "moved line" as a "recommended track" / "recommended route"???
In my opinion (using the information posted here in this thread, some of it directly from Navionics), it seems not only plausible, but quite likely!!!

And, further I REALLY do hope that Giuseppe Carnevali will clarify this for us all....
(Although this may be another reason for those of us "old timers" to still be proponents of paper charts.....that' a whole 'nother discussion!!!



4) Perhaps I should just sum-up my comments / queries....
a) Rolf, sorry to hear of your tragic experience!!
b) Bob Stewart, THANK YOU for taking the words out of my mouth!!
c) My 2006 Navionics Platinum Charts show this area correctly, with rocks/obstructions/shoals, and do NOT show any pass/cut, nor any "recommended track" between these two islands....
d) Would someone here (maybe Giuseppe Carnevali ???) confirm these issues/problems/errors are on the Navionics "pc navigation software charts" and/or "iPad/Tablet App charts", and/or "Navionics on-line charts"????
e) Is it possible / probable / likely that either a "software guy" / "proof reader", or the software app itself "moved"/"re-drew" an accurate "bearing line" changing it into a "recommended track" thru shoals and obstructions????



5) And, finally my 2 cents of Bahamian cruising advice/recommendations from my personal 45+ years of experience in the Bahamas....
a) use your eyeballs and depth sounder!!! (and binoculars / compass)!!
b) use the often poo-poo'ed "Yachtsman's Guide to the Bahamas"!!
c) use "official" gov't paper charts (US DMA / NGA) and "Explorers" paper charts...
d) do NOT rely on electronic charts, and/or iPad/tablet Apps.....nor any electronic products that have "not for navigation" warnings/disclaimers, etc...


Okay enough of my ramblings....
Hoping to read some clarification on my queries (from Navionics???)

Fair winds to all, and especially to you Rolf!!!

John
s/v Annie Laurie

[ka4wja]

Thomas,
I'm with you on this!!
But, if you read over my recent post (#207), you'll see that my 2006 Navionics Platinum Charts show NO such recommended track, NO passage at all between Guana Cay and Fowl Cay....just rocks/underwater obstructions / shoals and lots of shallow water....

Originally Posted by cagney

What survey does Navionics base the recommended track between Guana Cay and Fowl Cay on? No other chart maker has a recommended track here. Some has a dashed line area limit through the passage, but nothing more.
Just a straight, no nonsense, answer will do.

So, whatever answer you get, you should ask further how whatever data they do have is applied to their various products (Navionics Charts for chart plotters, vs. "pc navigation chartography", vs. "iPad/tablet apps")....


Good luck!!

John
s/v Annie Laurie

[MarkJ]

Originally Posted by ka4wja

my mind is reeling with the thought that some "software guy" or "proof reader" saw a thin black line on the chart (the useful bearing line) and saw it leading from a waypoint to the end of an island (as a bearing line should), and thought that it should pass between the islands, and so he simply moved the line or re-drew the line!!!!

While this seems unconscionable (and outrageous) on the surface, and as such almost an impossibility, I'm left wondering if this is in fact simply what actually happened???

John
s/v Annie Laurie

Hi John,

I think your right and would suggest thats how its happened.

I dont think its "unconscionable" I think its just human error.

Imagine if you worked as a cartographer... even the best of them after 8 hours at the desk must start seeing lines superimposing over each other, wavy lines wiggling while you blink the tiredness from your eyes. See a dotted line and make your 1,000th click of the day at 10 to 5pm at the beginning of a long weekend.

This is an example of why people need a variety of ecn charts as well as the guide book, Pilot and Active Captain etc etc etc. We KNOW we can not rely 100% on any charts so we need to be on our toes in difficult areas such as Bahamas cuts, reefs, shallows, river bars, channels and canals, ICW's in all their world wide variations.

Human error is a thing that we all do. Cartographers are normal people too, but with an incredibly boring, repetitive job at times.


Mark

[Giuseppe Carnev]

Wow!
I did not expect to receive so much feedback in such a short time, so I will have to respond to one issue at a time.

Let me start from this reference: "Every chart I bring up shows that submerged jetty extending out from land towards the C9 buoy, except Navionics."

if you check on any of our mobile apps, or on a plotter that displays the community edits, you will see that the rocks have been reported since last summer.

This shows how powerful the Community Edits and the Freshest Data are.
Once again I would like to repeat that "all charts have errors", no exceptions, as the grounding of the USS Guardian reminds as one of many many examples.

Infact if you do a similar search more extensively, you will find many rocks reported by community edits, which are not reported in any other charts (government or private). But those rocks are there, and can be seen on satellite imagery.

So the issue is: what can be done about it?

Navionics feels that communty participation is the most powerful strategy available, and I think that this example supports it.
We have done a lot of work so far, but it is still work in progress: our own web viewer has it under development and will go live soon, meanwhile we are working with our partners to make sure that their plotters also support the community layer; we also have many other things in the roadmap to make the participation more easy and rewarding. Stay tuned