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Practical Sailor Advisor: Using Laptops for Nautical Navigational Purposes

Picking Nits
I am using a laptop computer in the cockpit for navigation purposes. My problem is the "washout" appearance of the charts due to reflected light. I can barely see the screen in bright daylight. I have tried making an enclosure around the laptop, but this is cumbersome and results in little viewing improvement. Do you know of a flat screen monitor that I can connect to my laptop and mount remotely that has good viewing in bright daylight?

-Jim Hammond
Naples, FL

Thanks for your query. Ruggedized laptops and marinized displays have undergone a substantial evolution since Practical Sailor last addressed these topics (Nov. 1, 1997). In that piece, we didn't thoroughly cover screen viewability standards as the units discussed were intended primarily for interior use in the nav station. So here's an update:

Presuming that you're talking about flat panel LCD displays, there are several on the market that would serve your purposes. What you and other sailors really need to pay attention to is whether or not the item is marinized and what its nit measurement is. (The luminance of a computer screen—that’s the scientific term for its photopic brightness—is specified via a measurement of candle power per square meter, or nits.) Most LCD screens on laptops put out somewhere between 80 and 200 nits. However, screens that are labeled "readable" in full daylight usually put out more. For the sunniest of days, experts tell us that you really need a screen with an output of at least 1,000 nits. Nauticomp, for example, makes two such screens, both of which are quite pricey. That company's Signature Series 15-inch flat panel display, which puts out 1,600 nits, runs anywhere from $4099 to $4999 depending upon the options you specify. More information on this product as well as on-board computers in general is available at this website: www.marinecomputer.com.

One word about marinization: Most manufacturers use their own terminology to describe their products' resistance to the incursion of moisture, and there exists a variety of standards that can be cited. That makes it difficult to compare one unit with another. The National Electronics Manufacturers Association, or NEMA (not to be confused with the National Marine Electronics Association—NMEA) has two standards—4 and 12. A product with NEMA 4 designation can be drenched and still function fine, but one with a NEMA 12 rating can only withstand drips.

Two additional suppliers of daylight viewable, marinized monitors with NEMA 4 ratings are DataStar Marine (www.datastarmarine.com) and AutoNav Marine Systems (www.autonav.com). Both companies offer monitors that put out 1600 nits.

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Rigging Replacement
The recent survey of my O'Day 39 recommends replacing the standing rigging because it is over 10 years old. I am a cruiser and use the boat about 30-40 days per year. Because new rigging costs about $4,000, I would appreciate your advice on this issue.

-Frank Hartvelt
Via e-mail

Wire rigging can certainly last longer than 10 years, depending upon the use and care it has received, as well as the geographic location where it's spent the bulk of its life. However, older wire in particular should be carefully inspected for meathooks, kinks at the toggles, tangs, spreader ends, etc., and corrosion at the terminals. At any sign of those things, the wire needs to be replaced.

Of course, if you want to be truly certain, you should confer with a professional rigger and have that person examine your rigging as some wear and tear (like metal fatigue in rod rigging) is harder to detect.