Do you like the time on your wrist expressed with traditional hands or in digital form? Or has your cellphone display supplanted wrist watches altogether? In a world of ever-increasing man-machine interfaces (MMI), we get some choices and thus develop our own preferred MMI styles. Yes, even a portable timepiece is a machine, likely the first you ever interfaced with, and if thinking of one as such seems weird—if tracking time is totally second nature—then that particular MMI style is working for you. I bring this up because some interface self-awareness is important if you're shopping amongst the plethora of new NMEA 2000 instrument systems seen above. Each of the five brands represented can do most anything a helm gauge ever has, and often more, but there are many factors to consider in search of the style that's right for you.
First let me note that this column is a follow-up to my June 2008 feature "Down to the Wire," which examined what's going on behind the testing-lab scene above. Essentially we're in a new age where all those displays are connected to a similarly mixed array of smart sensors using a NMEA 2000 network. Those "analog" wind dials, for instance, just look that way; in fact, each is picking the same standardized digital wind-direction message off the bus and using a stepper motor to drive the pointer, not unlike a modern "traditional" watch. If designed to do so, all the LCD screens can also show wind direction, at least in numeric form, and some could graphically fake an analog wind display that's arguably snazzier and more informative than any real one.
So let's start this overview with design philosophies. Both Simrad and Furuno went somewhat old school with their similar IS20 and FI-50 instrument families, each of which includes several dedicated pointer types—wind, compass, or rudder angle—and two grayscale LCD models. Let's call Furuno "oldest school," as its three-line Digital and big-digit Multi use segmented LCDs are legible but cannot do the sort of bit-map graphics possible on Simrad's dot matrix Combi and Multifunction screens. A much larger distinction, though, is seen in the Raymarine ST70, Garmin 10, and Maretron DSM 250, all of which are high-resolution color designs meant to serve singly or multiply as whole families of data displays.
Now, as you may well know from experience with the multifunction display(s) at the center of your helm, such broad functionality also means multimenus, multipage setup screens, etc. The ST70 addresses this issue by having you initially choose from a wide variety of vessel types, each signified by a cute icon, and then automatically enabling as many as eight appropriate screen pages. The GMI lets you choose groups of focus-oriented default screens—Surface (speed, heading, etc.), Water, and Fuel, so far—or your own custom set. I say so far because, as I described in June, the firmware in all these instruments can be upgraded (and the new Garmin, in particular, seems unfinished). Even the Maretron display, which has been around in grayscale form for years, is still getting improvements yet lacks any beginner help beyond a single set of default screens.
Sooner or later, though, you'll probably want to maximize your all-in-one by building custom screens. You'll find that the ST70 is brilliant at this task, stepping you through the process with cheerful graphics and letting you split screens most any which way, each window often able to express info in a choice of graph, bar, dial, or digit. The ST70 also boasts the longest list of N2K PGNs, i.e. data types, that can be displayed. There's still room for improvement, however; for instance, the ST70 graphic speed dial cannot yet show the useful Average and Max markers nor the sexy shadowing, seen on the GMI 10 above.
But note, too, that neither instrument's speedo can yet be scaled to your boat's maximum speed, and what skipper wants to look at how fast he or she can't go, no matter how slick the screen? This is the sort of "Why not?" thinking you get into once you realize how powerful and malleable these color all-in-ones are. And trying all three brands compounded that problem; now my ideal instrument combines the Raymarine's super-clever operating system with the Garmin's delicious graphics and the Maretron's deep diagnostic and configuration abilities.
But such thinking might not be your MMI style at all, in which case you could have an installer set up these color displays to do a few tasks well, or you might consider the simpler Furuno and Simrad families. Actually the IS20 Graphic Multifunction is in the middle of this range, able to page through eight customizable screens, even graph any data value. The Combi, on the other hand, only knows a few PGNs like speed and depth and only has four preset screens. You may never open its manual, as is also true of the FI-50s, though their font size and graphics limitations make their setup routines somewhat inscrutable.
Of course, how well you and a given instrument get along involves several other factors. A big one is readability in various light conditions, and it's surprising how many solutions to that issue are represented in the test array. The GMI, for instance, obviously has the brightest backlighting—and is the only instrument here that needs its own power cord, instead of using the N2K backbone's supply—but beware indoor comparisons. The ST70 screen is also transflective, so in direct sunlight it competes well with the GMI. Meanwhile the old-school FI-50s use the newest power-efficient OLED backlighting, automatically adjusted, too. Simrad offers a choice of white or red night lighting, along with dark-for-light screen inversion. And the DSM 250 offers eight color palletes, each with three customizable intensity levels.
I'm trying to realistically photograph the test array in a wide variety of natural light; please visit my blog Panbo for these and additional information on factors I didn't cover here, like alarms and more especially neat info display details I've come across on all the tested brands. I'll also be trying them with an engine simulator borrowed from Lowrance, which incidentally has its own interesting selection of NMEA 2000 instruments. But before I close, I want to note that whereas any of these display choices will almost undoubtedly have GPS input, they could therefore display time with atomic-clock accuracy. In fact, a few already do, and the ST70 even has an alarm function iconically represented by one of those old-fashioned clocks with bells on top. Maybe that's your style?
This article originally appeared in the July 2008 issue of Power & Motoryacht magazine.