Features February 2008 Issue

Finding Your Way: Testers Look at Three Types of Hand-Bearing Compasses

Five hockey-puck compasses, four vertical-grip compasses, and one monocular compete for the title of best coastal navigation aid in their class.

Hand-Bearing Compass
Ralph Naranjo

When taking readings with a hand-bearing compass, some navigators find it easier to hold the compass close to their dominant eye, while others prefer to use a partially extended arm. When held a foot or so from the eye, the Weems & Plath compass, pictured here, shows a 10-degree card range.

Making bearings is one of the cornerstones of traditional navigation, and even in a world dominated by GPS fixes and an ever-growing commitment to digital charting, a hand-bearing compass and the information it provides continue to be of significant value.

These handy, compact magnetic compasses, with their built-in sighting mechanisms, allow users to accurately measure a relative bearing from a vessel to a recognizable mark, lighthouse, or other known location. Armed with two or more bearing lines, a navigator can accurately fix his or her position on a large-scale nautical chart. A single object shot as both a bow and beam bearing can provide a sailor with the "distance off," or range to, an object. And during a race, the regular use of a hand-bearing compass will tell whether a competitor is gaining or losing ground. In short, these versatile handheld navigation instruments are very user-friendly, and the latest models are better than ever.

Most skilled navigators retain a backup plan just in case the lights go out, the GPS goes kaput, or it and the backup handheld suffer from a systemwide glitch. Consequently, visual bearing-taking and careful chartplotting remain a valuable part of any contingency plan and a regular part of the coastal navigation routine. So, we decided to once again put hand-bearing compasses to the test.

What We Tested

To get a feel for the range of products available, we gathered up a cross-section of hand-bearing compasses. We tested the three main types: hockey-puck style, monocular, and vertical handle. All of the vertical-grip units and the monocular required battery-power for backlighting at night, while none of the hockey-puck models needed batteries.

The hockey-puck compasses we evaluated were the Mini-Morin 2000, made by navigation-equipment specialist Vion; the Iris 50 from Plastimo, a French company operating in the U.S. as Navimo USA; the SportAbout (model X-11Y) by well-known compass maker Ritchie Navigation; Vion’s Axium 2; and a compass from Weems & Plath, retailer of traditional navigation tools. In the vertical-handle group are the Plastimo 100, a compass by Davis Instruments Corp., and the Nexus Universal 70UNE made by Brunton and distributed by Celestaire. One monocular rounded out the field: the DataScope by KVH Industries.

How We Tested

Testers evaluated each compass on the water to rate them in real-world conditions and also tested them in a more clinical setting. We rated the accuracy of each, noting deviation from fixed bearings. We also measured how well damped each unit was and how long it took for the card to settle on a fix. The compasses were tested in varied light conditions, and night-time operability was noted. We measured effective operating angles, noting when a compass card began to drag.

Like a baseball player choosing a bat, we found that no one design fit all tastes, and the nuance in how these units are held, handled, and used is the most important factor in choosing which one is right for you. For example, navigators who prefer to hold a hockey-puck style compass close to their cheek, minimizing arm wobble, preferred the Mini-Morin or Plastimo Iris 50. Both of these units showed a very readable scale when held close to the eye. Other testers were more comfortable using the hockey-puck compasses with a partially extended arm, preferring the relationship it provided between the target and the numerals displayed in the optical magnifier. The Vion Axium2 and the Weems & Plath worked well in this way.

The Davis’ Alignment System


The Davis’ alignment system (like a gun sight) is user-friendly, but its slow-to-settle compass made scale reading difficult.

Plastimo Iris 50

This compact rubber-clad compass has a nicely engraved card, making its close-to-the-eye reading crisp and bright. In night-time conditions, its card illumination made bearing-taking easy. The Plastimo’s performance was very good.

Bottom Line: Though not the least expensive, the Plastimo Iris 50 represents a balance of good performance, quality construction, and moderate price. It gets the nod for Budget Buy.

Ritchie Sportabout

Although the Ritchie SportAbout hand-bearing compass fits the dimensions of the hockey-puck style of compass, it functions differently than the others tested. This small, dome-style compass lacks the optical card reader used on the other units. Instead, it relies on the line-up and shift-focus procedure of the vertical grip units, a process that adds error rather than accuracy to the mix, in our opinion. This is due to the human eye’s inability to focus close up and far away at the same time. The advantage of an optical card reader is that the design shifts the focus of the card numbers so that they appear very legible even when the eye is focused on a distant object.

Bottom Line: The top slot sighting groove introduces error, and the card’s tendency to drag and lock with only a few degrees of heel make the least expensive unit the poorest performer, in our opinion.

Vion Axium2

The Vion Axium2 is nearly identical in looks to the Weems & Plath compass; however, the Axium2 has a red lubber line that the W&P doesn’t. Although most testers felt the lubber line over-complicated sight taking, they noted that the compass is well made and very quick to dampen.

Bottom Line: For those who prefer taking sights with a partially extended arm, the Axium2 is worth a close look.

The KVH DataScope


The KVH DataScope got high marks for accuracy and ease of use. It spit out bearings almost instantaneously on its built-in digital display.

Vion Mini-Morin 2000

The simple, legible single-color, single level of numerals on the dial make the Vion Mini-Morin 2000 very easy to read. A distant object is stacked atop the numbers in the reading slot, and the one directly under the object defines the bearing. When held close to the eye, a 10-degree range of bearing appears, and as the unit is swung to place the object in the center of this scale, slight changes in angle to the horizon do not influence the reading.

Bottom Line: The time-tested Vion Mini-Morin 2000, one of testers’ top two hockey-puck picks, gets our recommendation.

Weems & Plath

Very similar in design to the Vion Axium2 (minus the lubber line) the Weems & Plath compass’ card is extremely well damped. When held a foot or so from the eye, the compass shows a 10-degree card range in the viewing slot. For some testers, this slight projection of the arm lessened squinting and improved the readability of the scale.

Bottom Line: The second-most-expensive compass in the test, the Weems & Plath tied the Vion Mini-Morin 2000 as testers’ favorite hockey-puck device.

Davis Illuminated

Slotted gun sights and a vertical handle allow this unit to be effectively aligned with the object being measured. Unfortunately, the small-diameter, unmagnified compass card is hard to accurately read while holding the target in the sights. Rougher conditions with increased pitch roll and yaw can mean error associated with erratic card swing. The Davis has only a small range of tilt that is free from card drag, and this proved to be an undesirable trait. For night-time use, the Davis requires two AAA batteries.



Bottom Line: While the Davis’ price is right, testers found its performance less appealing.

Brunton Nexus Universal

This bowl-type, vertical-grip compass with a battery-powered red diode light is bulkhead or flat-deck mountable, and capable of being used as a small-boat steering compass as well as hand-bearing compass.

Its card design allows front or back lubber-line reading, and it proved to be a nicely damped, universally pivoting compass. The downside of this unit—and the Plastimo Iris 100 we tested—is that when they are used in a hand-bearing context, the dome prevents the sighted object from being directly stacked on the lubber line, making sighting a little less efficient.

Like the Davis and Plastimo Iris 100 compasses, the Nexus Universal requires battery power for backlighting. It takes two No. 357
batteries, which are considerably more expensive than AAAs.

Bottom Line: If versatility is important, then the Nexus should be considered. However it costs more than similar products and battery replacements are more expensive.

Plastimo Iris 100

This unit was the largest hand-bearing compass we tested, and like the Nexus, could be mounted as a small vessel’s steering compass. It was well damped but prone to the same sighting difficulty as the Nexus. The Iris 100’s night light is battery powered (one AAA battery), and when testers shot bearings on Morse A buoys and other devices briefly lit at night, the Iris 100 did a very good job.

Bottom Line: Of the vertical compasses tested, testers were split between the Plastimo Iris 100 and the Brunton Nexus. However, the Plastimo is slightly cheaper, requires fewer and less expensive batteries, and it has the best warranty of the vertical units. It gets our recommendation.

KVH DataScope

The lone monocular tested, the KVH DataScope was a performance standout. It combines a 5x30 monocular, digital compass, electronic rangefinder, and a chronometer in a waterproof, handheld unit. Its design merges the concept of sighting cross hairs embedded in a high-quality monocular with a first-rate flux-gate compass design. Not only does the chip technology afford recording of nine bearings and an automatic averaging capability, but there’s a nifty built-in range calculating function, chronograph and other valuable features.

In order to avoid an absolute apples-to-oranges comparison with the KVH and the other hand-bearing compasses tested, we used Steiner Commander V binoculars for the comparison. The evaluation team split down the middle on which was better for sight taking, the Steiner or the KVH. Both deliver amazing accuracy, and both will be evaluated further in an update of bearing measuring equipment.

Due to the KVH unit’s flux-gate compass direction sensing system, the unit must be calibrated before initial use. The manual provides an easy DIY approach to calibrating the instrument.

The only negatives testers found with the DataScope were its slightly finicky battery installation, the easy-to-lose eye cap, and the high cost of the unit. This being said, the KVH DataScope delivered the most accurate bearings in all conditions. 

Plastimo Iris 100 and the Brunton Nexus Universal


Both the Plastimo Iris 100 and the Brunton Nexus Universal can be mounted for use as a steering compass on a small boat.

Bottom Line: The unit proved as useful, accurate, and user friendly at night and in rough conditions as it was on a sunny, calm day. Its major drawback is its price tag: $320. For that hefty sum, we’d like to get more than a one-year warranty.

Conclusion

The top performer and PS Best Choice is the KVH DataScope, our reigning "king of the hand-bearing compasses." Its accuracy and numerous features make it a very handy navigational tool. At $320, the DataScope isn’t for everybody. If you’re looking strictly for a backup device, we suggest going for our top pick of the hockey-puck compasses, which weigh in at one-third the cost of the DataScope.

Picking a winner in the hockey-puck group was a tough call. In fact, the Weems & Plath and Vion Mini-Morin 2000 compasses—both non lubber-line scales—ended up in a dead heat, tying for top puck picks.

The vertical-grip compasses take a backseat to the hockey pucks, unless you’re a small boat skipper who wants the versatility of a hand-bearing compass that serves double duty as a steering compass. If this is the case, we recommend the Plastimo. It performed as well as the Nexus and will save you a few bucks.

Bearing taking and piloting are not as arcane an act as some digital charting advocates might feel. In fact, many software systems allow for easy input of LOPs derived from a compass fix, and staying current with this traditional skill will stand a crew in good stead when and if the lights go out.

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