Throw away yer paper charts

Ooh! I can see this being as much fun as the DSC radio threads, but I have to go to bed, so continue tomorrow! <g>
B

<hr width=100% size=1>Catapultam habeo. Nisi pecuniam omnem mihi dabris, ad caput tuum saxum immane mittam.
 
/forums/images/icons/blush.gif Maybe for all except the part about only running the nav application and nothing else contemporarily on the machine if one is dependant on the nav application, we should move to a computer forum.

Regards

John

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My only knowledge of Apples in recent times (last I used was a Lisa) is the school network. 50 machines. Over the last school year 30 or more have crashed each day to the extent that a simple reboot wont resurrect them, and require IT intervention.

We have about 2000 users running our software in a windows environment - if the same ratio suffered crashes like that I'd have been out of business decades ago!

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Its a reasonable choice to use / not use electronic chart plotters or paper charts since they are reasonably equivalent. They achieve the same results. The decision as to which depends on your circumstances.

But not using a GPS is, IMHO, daft. There is no way that DR /EP nav remotely gives the same reliability and accuracy of position fixing, and the three point fix is not always available. Its rather like sailing without a VHF and relying instead on shouting!

Maybe you use a scull, flax sails, wooden blocks, stone anchor etc?

<hr width=100% size=1>this post is a personal opinion, and you should not base your actions on it.
 
You are correct, however the crucial point is that the ECDIS system includes chart corrections etc. and as far as I am aware, none of the chart plotters or PC systems that are used by the leisure fraternity are included in the authorised ECDIS systems. I also know that C-Map are introduciong a methodology that should allow C-Map users to qualify. Meanwhile unless you have a ECDIS system you must have paper charts.

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> C-MAP don't have non-Microsoft software development libraries for rendering
> their charts...

How do dedicated chartplottes (like Raycharts) draw their charts? Do they implement the rendering libraries themselves, or are they secretly running Microshaft Windows underneath?

<hr width=100% size=1>One day, I want to be a real sailor. In the mean time I'll just keep tri-ing.
 
Chart corrections are issued for official charts electronically and can be applied to their S-57 vector (what there are of them) and HCRF raster charts even when used by at least many non ECDIS and uncertified systems. 'tis a fact because that is what I do and believe that it is so with at least UK (UKHO), Australian (AHS), NZ (LINZ) and USA (Maptech) official charts on many such systems.

I think that you would find that in most jurisdictions (cannot speak for the UK) there is no part of the legislation that requires pleasure vessels to carry any particular charts at all. For example, New Zealand is one of the few countries where a pleasure vessel is inspected and informally expected to be carrying charts relevant to its route if clearing NZ for a foreign port, but even so I am not aware of any specific requirement by the law of the NZ flag administration that they be carried. In any event if an accident an insurer could only not respond or a prosecution of any worry be taken by the state against the boat if it were provable that the lack of a paper chart was a cause of the accident eg if one ran onto a rock using electronic charts only but the charting system was operable at the time, the fact that you did not have a paper chart would be irrelevant unless it could be shown that having that on board would have prevented the accident.

Note that I am not proposing the short carrying of charts in whatever medium, just what the situation is as I understand it to be.

John

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They generally run their own OS, but rendering software is available as source code which they probably (?) buy in.

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We use professional ECDIS on our ships. This runs (or did when I was last on board) Windows NT and is a large dedicated terminal with a huge colour screen. A second terminal provides backup, and either can be used to control the dynamic positioning (DP) when holding station using azimuth thrusters. Even these were prone to application crashes, though the NT system was pretty stable. Software patches were a routine on nearly every port call. Both terminals are equipped with large UPS cabinets and there is no shortage of backup power.

Windows OS which are not built on NT (eg W95, W98, W2000, XP) have no thread error checking worth talking of - this is the main difference between the standard and Pro versions, the latter being based on NT. This was why NT required such large memory resources compared with W95 when it first came out.

The power used by a laptop is enormous in terms of battery resources - roughly equivalent to running a sailing vessel with nav lights, radar, and autopilot.

Given the power requirements and OS reliability issues, it makes no sense to me to use a laptop for any critical task on a small sailing boat on any passage more than a few hours. Power may not be such an issue on MoBos and larger sailing vessels, but for me there's a hell of a long way to go before I start to wallpaper the house with my paper charts.

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Hi Tom

I generally agree with you and for the satisfaction of others point out that your knowledge of the innards of ECDIS is likely to be greater than mine.

But I do disagree on the power usage of a laptop. Our current charting system (Endeavour Navigator) maintains a full legal log which cannot be disabled (even when planning) - including the logging of every NMEA sentence received from the sensors so the hard disk runs continuously - and its current draw would be well under 3 amps @ 12v - much the same as that of our anchor light alone. Furthermore, on long routes with no nearby dangers eg oceanic or clear coastal, it needn't be run except at fix times.

I would not rely on a single laptop either, but an important advantage of using a charting system is that one may be inclined to carry more charts including those of refuges which may not be part of the planned route (especially so for us as all our electronic charts are essentially free - approx GBP20 for the lot - and that includes the planning charts for the whole of the Pacific plus a number of the Pacific Island groups). Another, is it may make an independent check for dangers on the planned route or if no such route such a check on the current heading extrapolated.

In my view a backup could be another computer (assuming two reasonably independant power sources) or a smaller set of paper charts than would normally be carried, perhaps complemented if the need felt by printouts of possible refuges or areas having considerable dangers taken from the electronic charts. In our own case I now carry fewer paper charts and no longer correct them unless it is a matter of great effect.

John

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Cant give you chapter and verse from the official blurb, but it is my understanding that the latest Solas regulations in UK (and presumably the rest of the EU) gives the authorities the power to ensure not only that you have an adequate passage plan for your trip, but also that the boat is adequately prepared for such a trip (and this includes items like radar reflectors, safety gear and appropriate navigational equipment that is working and in date.) IIRC the US Coastguard have similar powers over US flagged vessels, but am not sure where they stand in relation to foreign flagged vessels.

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Good heavens John, I can see your anchor light from here! Mine is only 10W.

Power usage depends on many factors (screen size and technology, backlighting level, processor speed, hard drive,ambient temperature) but I'm typing on a Toshiba Satellite Pro 4600 laptop which has an Intel Celeron processor. I measured a max current of 4A at 15V, or 60W. There is a lot you can do to reduce this power with screen savers etc, but it's probably safer to use 'worst case' for this discussion.

Given that the most common method of supplying power is an inverter, and allowing (say) 85% efficiency puts the power consumption at about 70W which is about double what you are measuring with your leaner setup. In either case, a sailing tricolour light for a boat under 20m is likely to be 25W and so the laptop power usage is highly significant.

In my case, with only 160AH available (320AH batteries) the laptop alone could flatten my domestic batteries in a little over 24 hours even if I had nothing else switched on. I would need to run the engine for an additional 2 - 3 hours per day just to compensate for the laptop usage.

If the laptop can be put into sleep mode between fixes, then this has a significant impact on a long passage, though you cannot then log sensor data to the hard-drive.

So, it's paper for me- at least until I've saved up enough for my 65 foot baby with auxiliary generators.

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by tome on 30/04/2004 13:57 (server time).</FONT></P>
 
Hi Mark

I believe that you are correct in that. My experience with the UK legislation is to do with commercial vessels but the relevant international document is Solas V (as it is generally known) and that is enacted in the UK by the Merchant Shipping (Safety of Navigation) Regulations 2002. Pleasure vessels under 150 T are exempted from much of it.

I believe that there is nothing in the Safety of Navigation Regulations which specifically says pleasure vessels (at least of the size most of us own) have to carry charts. The expectation is that navigation documents (including tide tables, pilots, etc), without being specific, sufficient for safe navigation be carried and that information need not be in a formal document but may be sufficient to have just memorised it for a simple voyage. For the majority of pleasure vessels (in most western countries 85-90% are under about 6 or 7 m, and all probably mostly operate in limited waters well known to them) charts are not required for safe navigation in the waters and limits they normally operate in.

I had a quick look on the MCA site (which is now a very good one I see) and there is a brochure there on what SOLAS V means to pleasure vessels - it makes no mention of the carriage of charts being mandatory, again just that what is needed for the prudent conduct of the voyage is to be carried.

So, out of that one can also say that there is no requirement for pleasure vessels to carry a backup to any electronic charting/plotter system they may use except where it is prudent to do so for the safe conduct of the voyage. I suspect that for most voyages pleasure vessels make, backup would be redundant.

Again, I emphasise that I am not saying or promoting charts should not be carried, just that there is no specific requirement to do so that I am aware of. A corollary of that is that it is not mandatory, as many say it is, to carry a backup to an electronic charting/plotting system. The nature of most voyages undertaken by pleasure craft do not require charts to be carried but, of course, for some voyages it would be reckless not to do so.

Regards

John

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Re: Example

Yep.. have a friend out there right this very minute, doing a delivery to Brisbane from Melbourne... he is in the middle of Bass Strait ,amoungst the oilfields...was only taking his laptop etc, till I made him take my paper chartds.. guess what, they lost ALL power on day one. !!!!!!

Oh yes,they were hit by a gale last night.. me I like both
Brian J

<hr width=100% size=1>BrianJ
 
read with care..

This is a reference to the IMO specification. ENCs running on an ECDIS, etc.

If you have a yacht, this is NOT what you have aboard (unless she is a VERY big one!).

For one thing, the system must be fully redundant in all parts of the system...

<hr width=100% size=1>Que scais-je?
 
Tom - took your comment to heart about my anchor light being visible in UK /forums/images/icons/smile.gif. Thought I might make some smart comments about lighthouses etc, but instead decided to this weekend measure the currents and this is what I got. The currents were measured on the dc board by breaking the negative conductor at the termination block strips.

Anchor light (10W nominal, Aqua Signal 40) - approx 1.3 amps @ 13.2 v

Notebook computer - average approx 1.75 amps @ 13.2v
(Compaq, 1.2Ghz AMD Athlon mobile, running nav program, real time logging all NMEA from GPS, Wind, Log and Depth to hard drive, drawing track (albeit with the boat stationary) and displaying ex GPS heading and wind arrows, powering external 4xUSB hub, two USB<->serial converters and a USB mouse, screen active, battery fully charged, measured at 13.2v ship side of buck converter stepping up to 18v).

So computer uses little more than the anchor light, (I had previously assumed the PC used about 3 amps and the anchor light appeared to draw about the same on the dc board analogue meter). The computer drew about 0.15 A either sideof the average (rate of change over that range in 10ths of a sec) but that range is obviously affected by the multimeter's dynamics (a digital Brymen multimeter was used) but I have assumed that the average is fair.

Have to say I was pleasantly surprised and had not expected the computer draw to be so low.

Regards

John

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Windows XP is vastly more reliable than any other previous version of Windows that has come before it, which isn't saying a lot, and the Windows 2000 Servers that we run critical systems on run normally run for 6 months between restarts.

Agree about security issues - this causes more grief than anything else, although you can consider yourself unlucky if you get a virus at sea... (from a passing plague ship's wireless network ?)

One thing to bear in mind is that you are effectively changing the operating system every time you install or remove any hardware. One dodgy hardware driver can totally destabilise your machine. One comment on Windows I heard recently - "Windows makes it far too easy to do things you shouldn't be doing".

dave.
 
John

This sounds low compared to my measurements, perhaps because the PC battery was fully charged? I would expect around 3A mean with peaks of 4A at startup etc.

Even so, your measured consuption of 23W is significant for us and is probably about the same as our average fridge draw.

Having said that, I was on board Ian's boat the other day messing with his SSB and had a chance to look at his PC setup, which I have to admit is very impressive. We had a quick wander around the Med visiting some familiar ports on both vector and raster charts. However, he has 6 domestic batteries at (a guess) around 120AH each giving him more than double our capacity.

I would definitely go for a PC for passage planning, but still prefer my Yeoman plotter under way - guess this makes me a dinasaur, but I just don't trust in Gates or my batteries.

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