There are many choices of computer screens and like most things in life, experts recommend that you buy the best you can afford. And, just like computers, there isn't one type of monitor that is the best solution for everyone.
First off, there are three types of screens: cathode ray tube (CRT), liquid crystal display (LCD) and plasma, which is the newest and most expensive. Of course, they all come in different sizes and qualities.
If you're using a desktop computer, I suggest that you buy the largest screen that will fit in the available space. Next, you'll want the largest resolution, fastest refresh rate and smallest dot pitch available. The older VGA screens typically display at a resolution of 640 by 480 pixels. Today most screens come as a SVGA and support a display of 800 by 600 pixels. The expensive XGA screens support 1024-by-768 pixel resolution and are primarily intended for high-end graphics work.
The larger the screen size, the larger the viewing area and the more resolution available. For example, going from 1024 by 768 pixels on a 17-inch screen to 1152 by 864 on a 19-incher will yield 27 percent more chart on screen without shrinking the text. With a 21-inch screen you can increase the resolution to 1280 by 1024, putting 66 percent more chart on screen compared to a 17-incher. The newer large screens are capable of resolution of up to 1600 by 1200; however, at this size you'll find the text very cramped and your graphic board may not be able to deliver a full palette of colors or refresh the screen at a fast, flicker-free rate.
Before you rush out to buy a new larger monitor, make sure that your computer's video board can handle the higher resolution graphic displays and faster refresh rate. The biggest drawbacks with CRTs are their heavy weight, very large size, flicker rate and some of them max out at lower resolutions.
Liquid crystal displays-either a flat panel stand-alone monitor or as part of a notebook computer-come in two different screen types: a dual/high scan, DSTN, and an active matrix, thin film transistor (TFT) screen. The TFT is brighter and crisper than the DSTN screen and is easier to see at wider viewing angles. You must be directly in front of the DSTN to see it clearly and the picture starts to disappear as you move to the side and view it at an angle. Even though the TFT screen is more expensive, the wider viewing angle and brighter, crisper screen make it the screen of choice on a boat. Interior flat panels start at 10.4 inches and 640-by-480 resolution and go up to as large as 25 inches on an XGA screen. They are expensive but their lighter weight and thinner size make them an excellent choice where space is limited.
The new and very expensive plasma screens are bright and colorful but, with low resolution, a bit fuzzy. They also need an expensive graphics card that supports their wide-aspect ratio. Today they are not considered economical for use on any but the largest of yachts.
The final screen consideration is brightness. All types of screens are usable at the nav station or bridge but not in the cockpit in bright daylight. To be daylight-readable, screen brightness should exceed 750 nits and the best screens will exceed 1,000 nits. Typical DSTN screen brightness is between 100 to 150 nits. Daylight-viewable displays are either 10.4- or 12.1-inch SVGA active matrix LCD screens in a waterproof enclosure. Optional touch screen operation is available and recommended for use at the helm or cockpit where a mouse can be difficult to use. If a touch screen is not an option, you may want to consider using an IR mouse or pointer.
So, what's the bottom line on screens? On a larger boat, stick with the largest CRT screen. They are still the best value and today's largest monitors range from 27 and 31 inches to nearly 40 inches diagonally. If space is limited, go with a flat panel monitor. For smaller boat, choose a TFT screen or a daylight-viewable if the screen is at the helm or exposed to bright sunlight. Some of the newer GPS plotters come with a full-color daylight-viewable screen and as prices drop, the daylight-readable screens should be a serious consideration for many sailboat owners.