The Favor uses a combination of digits, icons and graphics to display information. For example, the No Decompression Time Remaining can be read precisely as a digital countdown or checked quickly from a colour-coded bar chart Ð as long as some bar chart remains you are not yet into decompression. A yellow segment warns that you are within ten minutes of entering decompression and need to be more attentive.

Screens are selected according to whether you are underwater or on the surface and many - such as dive planning and the custom programmes used to set the clock, choose the altitude band, or select the log recall - only appear when deliberately called up. This helps to avoid sensory overload for the user.

Surface displays include a calendar clock and pre-dive planning that scrolls no-stop times for depths from 9m/30ft to 45m/150ft in 3m/10ft increments in about 45 seconds. A Perspex user-replaceable shield is supplied to protect the computer screen from damage.

It is very important that computer displays are easy to understand, especially during the dive, otherwise confusion can reign. Our interest was primarily in how the Favor shows the diver his or her status underwater, where you can't check with the handbook if there's any ambiguity. We were especially keen to check out the decompression display as this is an important safety aid for divers who unintentionally go over their no-stop times and may have to follow an unfamiliar display while stressed.

During a no-stop dive you can read off no-stop time remaining, elapsed time, current depth and altitude zone. Maximum depth and temperature alternate every few seconds.

Decompression, whether entered into intentionally or unintentionally, is a fact of life. We feel that to test any computer thoroughly it must be evaluated in decompression mode. Although Suunto recommend against using the Favor for decompression diving, the computer is well equipped to handle it. The algorithm is an abbreviated version of that built into the more expensive Solution and EON models and the decompression range is slightly more restrictive. The maximum decompression time the Favor handles is 63 minutes, with the deepest stop set at 12m/40ft. This is beyond the interest or stamina of most divers, especially those using air.

Once into decompression the Favor calculates and displays total ascent time and the depth of the deepest stop. On reaching the stop it indicates the proper decompression zone (the maximum and minimum depth of water you can decompress in) and violations such as ascending above your stop or surfacing without completing all decompression.

Circumstances conspired against us and only two of the team made decompression dives. One was a comparatively new diver making his first stop dive, the other was experienced co-supervisor James Davidson, who made several decompression dives. Both went into decompression at 30m and were apparently unaffected by narcosis which might have influenced their assessment of the displays. However, Davidson may have been at least slightly distracted by the realisation that on one unplanned deco dive he was making his hang with only a shark for company. The score for understanding and using the displays was 80 per cent.

Violations

At no point were our test team asked to deliberately violate the computer's recommendations. But, as can happen, individual divers exceeded the ascent rate of 10m/33ft per minute. The Favor uses a bar chart to indicate ascent rate. Violating the ascent rate results in the current depth display alternating with a 'slow' logo. This was the only violation seen during testing and received a score of 80 per cent from the two miscreants involved. Violation alarms are visual. Underwater, the display was easy to read in daylight. At night it performed badly when the lights were turned off, even after the divers had waited five minutes to allow their eyesight to adjust. This was not unexpected since the Favor display has no illumination of its own. Using an LED screen would use too much battery power and most computer manufacturers are working with light-retaining displays rather than powered ones. Suunto uses the latter approach on its 'Lux' range, but not on the Favor.

Surface Displays

After the dive the Suunto displays the time and maximum depth of the dive and the current surface interval, together with an indication of decompression or ascent rate violations. The no-fly time will be a minimum of 12 hours, in accordance with DAN safety recommendations. The Favor treats no-fly time and total desaturation time identically, so if desaturation will take longer than 12 hours, the no-fly time will be extended. This is unusual, as most tables and computers allow flying when the diver is only part-desaturated. Suunto istaking a very conservative approach. Surface displays were rated for ease of understanding and earned 80 per cent.

Other Functions

The Favor cannot be downloaded to a PC. However, it has a comprehensive on-board logbook than can be accessed by use of the three terminals on its face. Wet fingertips activate these. Nine dives are logged and scrolling through these provides information on elapsed dive time, maximum depth, average depth, date of dive, ascent rate and decompression transgressions, and how close you got to your no-decompression limits. The Favor also logs the total number of dives ever made, accumulated dive time and greatest depth (to 99.9m, if anybody wants to sit on top of Ras Mohammed and spool it down on a bit of fishing line) ever reached.

These terminals are also used to set time and date, and for choosing the altitude menu. The surface functions were only used by three of the team and one awarded the minimum mark because of a problem with his machine's terminals. This dragged the Favor down to 55 per cent. While writing this report we had no problems accessing information from any of the machines. The other team members rated it average and good and had no problems with the controls.

The Favor is available in a combo with a pressure gauge and an add-on compass. Our test units were wrist units. The strap passes through the instrument back, so there are no pins to break. At 36cm/14in it is plenty long enough. In this section the team gave the Favor an overall score of 55 per cent.

Test Team reports

INSTRUCTIONS 70%
PREPARATIONS 85%
DISPLAYS 80%
SURFACE USE 80%
OTHER FUNCTIONS 55%
OVERALL 75%

Test Team overall score for the Suunto Favor: 75 per cent
The Suunto Favor as tested retails for £192.50 including VAT.