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post #20 of Old 06-07-2010
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To me the biggest problems with using a laptop as a chart plotter (the original question) are: environmental; display; durability; design.

Heat - a big problem whether you're carbon or silicon based. If the laptops going to be running a lot, then getting the heat away from the electronics is going to be a prime concern. Many of the cruisers who use laptops have additional fans to circulate air around the unit to keep the internal temps down. Orienting it so that the heat naturally rises can reduce the thermal loads and prolong the life of the unit. And don't forget about cooling the laptop power supply.

Moisture - Then there's the problem of moisture - both salt and fresh. It's important to keep this away from the laptop. Most folks put their laptop away after use but if it's your navcomp, it might not be an option. You want to carefully consider where you'll be mounting it (and I recommend a firm mounting scheme), how you're going to get the heat away, and keep the water away.

Power - You've got to feed the laptop and unless the unit runs on 12VDC (wouldn't that be magical!), that means power conversion; either DC-DC or DC-AC-DC. Buying a small inverter may be more economically and utility feasible (AC for other appliances) than a dedicated DC-DC converter. I'd make sure the inverter works fine with the laptop power supply. And I'd carry a spare power supply too.

Display - there aren't many laptops whose display can be considered sunlight readable (at least without a hood, and probably without you wearing sunglasses). Size is nice but we've got a storage problem. I'd still get the biggest I could.

Durability - give very serious consideration to a ruggedized unit. They can be expensive but some military surplus units show up on the auction sites now and again. Considering the cost of these units, you may find it cheaper to buy 2 well built instead of 1 ruggedized.

I think we all agree that laptops weren't designed to run 24/7. But desktop/towers were. But many of us don't have the space for a tower, whether it be desktop, mini, SFF, or a mix. And a laptop's almost essential for us cruisers.

Design - I'd look for a brand name that might get me some support outside of your home country. I'd look for keyboard covers to keep the moisture out, a big drive, lots of memory, and good heat dissipation. External drives are a good idea as a backup device but if the USB/FW/eSATA ports go south and you've got all your charts on the external....

It might be worth considering getting a throw-away monitor that you can use in the cockpit when it's needed. Having a laptop that'll do that easily and supports the monitor/program resolution is worth considering.

It also might be worth getting an aux keyboard and mouse. If they get damaged then you can more easily replace it down island than the entire laptop keyboard.

If you shop carefully you can make that laptop do multiple duty. It can be your email link, movie/music source, photo editor, blogger, inventory manager, recipe cabinet, letter writer, and so much more.

Just not the navcomp. Just as the big white boats dedicate a computer to the navigation tasks, so should you. All it takes is one malware/worm/bug that you unwittingly downloaded to destroy your navigation source.

In full disclosure, I'll say that I sail with a laptop that does double duty as a navcomp. Every time I go to an internet cafe or log into a unprotected wifi network, or download email, I cringe. I run the usual software protection, keep up to date on software updates, and don't surf the net much. But I still have trepidations about something nasty getting into the navcomp.

And I've recently bought a second laptop (Mac this time) that has a PC partition and all the navcomp software as a backup and for planning purposes. It's my entertainment, paperwork, and blog unit.

So, I've got limited resources and space. What would I do?

1) I'd buy 2 laptops; one for general use and one for the navcomp. I'd buy the same model, outfitted the same. Make sure they more than meet the hardware/software requirements of the nav software. You don't need the fastest but I'd still get something near the top of the performance curve. Navigation software can be system intensive especially if you're navigating, recording waypoints/instrument data, or route planning.
2) I'd buy 2 external drives that are at least 2x the capacity of your laptop, have multiple interfaces, and a good reliability rating. I'd also consider getting externally powered drives in case the USB/FW port goes bad.
3) I'd demand restore and system disks for the computer. You're going to have to reinstall the software sometime, and having the disks with you rather than having to hunt all over the net to download the 5GB of files, search for a new set of serial numbers, drivers, and the support files, or pay for a DVD that should have come with the machine is not going to make you or I happy. Can't get or they won't give it to you without a fight? See #4
4) Before you add any programs to the laptop, back it up; preferably to a dedicated partition on the external hard drive.
5) Install the software and charts and back up to both external drives. Buy only the charts you'll use for that year. Chances are there'll be updates by the time you'll need them. If you download the charts, I'd burn copies of them to the external and possibly a DVD.
6. When you get the navcomp tweaked the way you like it; back it up to a new partition. Just in case.
7. Do regular backups to a third partition. That way you've got 2 chances to get your machine out of ER. Some backup software overwrites previous backups so having a dedicated partition gives you 2 chances to bring back the dead.
8. Give extra thought to mounting, cooling, and protecting the unit. One of the sweetest layouts I've seen was a vertically mounted laptop. The user installed 3 small 12VDC fans under the unit to force lots of air up along the back, the display was at eye level, the unit had a hood over the display to give some sun and moisture protection, and they had an external keyboard and mouse sitting on the desk. The could still access the DVD player, ports, and power plug. When things got tough they powered down the unit, bungeed the display closed, and put a couple trash bags over the unit; just in case.
9. Got some free time of feel like a challenge? Then consider networking the computers together. That way you can sit in the cockpit and still access files on the navcomp.

I spend the vast majority of my time in the cockpit when sailing. It's not that I don't like being below, but outside is where the action is; where I can see that just awash shipping container or long line or bilge oil slick or current/seaweed line. I've yet to see a "sunlight readable" display that can keep up with the sun for intensity, outlast salt water, or work as well as my eyes, ears, nose, and to a lesser extent, my brain.

My cruising routine is to use the navcomp to do the rough planning, then give the route a careful look-see on charts if I have them, or zoom in greatly (being aware that zoom is a two-edged sword) and check the route for obstructions. If things look OK, I generate a route and list of waypoints. I send the waypoints to the GPS and run the route. This tells me if there are conflicts with the GPS and navcomp. The navcomp gets shut down and the DGPS does the calculations, I control the autopilot, and we go off on our next adventure.

So, I'll stick to a boring GPS display with the basic info, do the hourly paper chart plots, and work on my fishing skills. If things get really tight, I may bring up a cheap display so I can see what the computer says as I navigate the narrow entrance.

But I sure can get a lot more accurate info by looking at the XTE on the GPS, looking at the changing water color, looking at the water state in the entrance, and lining up those range marks, than watching the tube. And if I go on the rocks, it's my fault, just as it is if I blindly followed the display. The questions is which navigation technique was better.

Capt. Douglas Abbott
USCG/MCA IV/C.I./M.I. 500-ton Oceans

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Last edited by oceanscapt; 06-07-2010 at 01:31 PM.
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