Computer Problems: Part II

This is the second in a threepart article on potential computer problems as reported by Undercurrent subscribers.

As you will see, there are many troubling problems that plague dive computers, making it essential that divers constantly monitor their accuracy and carry a back up.

Erratic Depths

When Jim Sicina (Englishtown, NJ) started getting erratic readings from his 11-year-old Oceanic Data Max Pro Plus computer, he sent it back for a repair. "I was charged $120," he recalls, "and given a oneyear extended warranty, which I thought was fair." A year later the warranted computer went erratic again, this time in a different way. He sent it back with an explanation of the problem and by return mail received a new Oceanic Data Max Pro Plus 2.

Alan Sankowski (Hoffman Estates, IL) and his wife took a pair of Suunto Cobra AIs on a dive trip to Komodo and experienced a nonrecurring depth reading problem with each computer. The couple normally dives almost identical profiles and checks each other's computers and gauges throughout each dive. During the first three dives, both computers' depth readings were identical (and in agreement with their backup computers). "On our fourth dive," recalls Sankowsky, "I saw my wife about 10 feet below our previously agreed max depth. After we had both ascended a few feet, we found that my computer was reading 8 feet deeper than hers." For their fifth dive, the crew of the Komodo Dancer lent the Sankowskis another computer as an additional depth gauge. "During the first half hour," says Sankowski, "my wife's computer read about a foot deeper. During the second half hour, the difference grew until her computer showed 8 feet deeper than mine." While the depth readings were inaccurate, all of the algorithms seemed to be functioning correctly, Sankowski reports. On more than 30 subsequent dives, both computers behaved correctly and were always in agreement with each other and with the backups.

The Sankowski's dive shop returned the Cobras to Suunto. No problems were found. "I'm not sure what to make of this," says Sankowski. "A large part of confidence in one's equipment is mental. Since we did not experience any problems in the last 30- plus dives, I've become less concerned with the reliability of the computers and more inclined to believe that the problem was a one-time issue."

For a trip to Cocos Island, Richard Jones bought a Cochran Commander computer. On his third dive it registered a major difference in maximum depth compared with his buddy's. "The computer was one atmosphere off. At 99 fsw, it registered 66 feet." When he returned, Jones went to the dive shop, Blue Water Divers in Oklahoma City, and asked for his money back, since he did not trust the computer. Instead, the shop offered to return the computer to the manufacturer and have it repaired. "I spoke with the manufacturer," Jones recalls, "and they promised to fix it, and if I was not totally satisfied they would return my money." But when the unit failed again that promise was not kept. Instead, Jones took the Commander to a competitive dealer who accepted it as a trade in on a Suunto Viper.

After a year, John Yasaki's (Oakland, CA) Suunto Mosquito began sporadically entering dive mode, reporting an arbitrary depth, and tracking dive stats for that depth. "It would trigger shortly after going to bed; upon awakening, I'd look at my wrist to find that I had been at 78 feet for the past six hours. Made for a longer than normal wake-up period, given all the deco obligation." The problems increased over the next six months, particularly in damp or humid conditions. "To tell the unit the dive was over," Yasaki recalls, "you had to pull the battery and essentially reset the computer." This proved particularly problematic "when you have geared up and hopped off the boat, only to discover that you're at 37 feet while floating on the surface. (If you took the unit diving while in this condition, it would register its initial depth plus your actual depth. Not great in the confidence-building department.)"

Aqua Lung replaced it, and the new unit worked well for several months. Then, at the end of one dive, Yasaki was using his primary Cobra to gauge depth for his safety stop. At 15 feet, the Mosquito registered only the time of day. "I dropped back to 25 feet," he says, "and the Cobra registered the change. The Mosquito registered a depth of 8 feet." Over the next few dive trips, Yasaki found that it would read varying depths while sitting on the bottom or would read the same depth while sawtoothing. "It would report a dive completed after reaching 20 feet, or would refuse to register any depth at all until about 40 feet down. It reported several sawtooth profiles along a 40-60 foot bottom as a series of two minute dives from the surface to 30 feet." He returned it to Aqua Lung, along with downloaded data from both the Mosquito and Cobra. They approved another swap, he says, adding, "Now I have a new Mosquito. It remains to be seen how well this one will work."

If you dive with a backup computer or with a regular buddy, it's a good idea to compare computer readouts, both underwater and during your surface interval. Don't expect them to be exact, no matter how close you stick together. But any striking differences may be signs of a problem requiring attention. And if you can supply data, as did Yasaki, you can solidify your case.

Computer Servicing is History

Other than to help you change a battery, most dive operators won't touch a problem computer. Even computer manufacturers rarely service returned units. If under warranty, they're generally replaced with new models. Outside warranty periods, practices vary widely. Since dive computer makers issue new models almost as fast as Dell upgrades laptops, technical support is no longer available on many models. Some survey respondents reported good results with older computers. Some reported nightmares.

"My Aeris 500 AI sometimes develops black screen disease," says Richard Jorgensen (Bradenton, FL), "and the buttons will not wake it. Aeris' solution for me was a rebuilt 500 AI for only $150." Since he was given no assurance that the problem was solved, he decided to shop for a new brand.

Bill Stacy's (Ruskin, FL) Seaquest (Suunto) Solution Nitrox works fine for the first dive of the day. But on the second dive, instead of displaying water temperature or the deepest depth, some mysterious percentage appears. The next day it's fine again for the first dive. Stacy reports: "I took it back to my dive shop, and they could find nothing wrong. I have received no satisfaction from the place of purchase or the manufacturer."

Donald Wilson's wrist-mounted Suunto Vytec occasionally locks out -- Wilson estimates once every hundred dives -- after the pressure drops to zero when changing tanks. The display reads "fail," and he is unable to reset the computer for several hours. It still shows depth, temperature, and time but does not show tank pressure, nor does it record and save dynamic dive details. "The owner's manual -- like all owner's manuals, a semidisaster -- does not show the way out of this dilemma, nor has anyone at Aqua Lung been able to help me," says Wilson.

Last year, Jim Tompkins' (Beltsville, MD) dive shop sent his original Uwatec Aladin Air-X to Scubapro to have the battery replaced. He was informed that the battery was no longer available and that he could purchase the current equivalent model of the Air X for $250. He says, "I was disappointed in Scubapro in leaving me with a $900 computer that has to be disposed of after the battery wears out." With so many competitive models available, one might wish to avoid any computer that must be sent back to the manufacturer to change batteries.

Computer return policies are clearly flexible, depending on the situation. Generally speaking, the better the relationship between your retailer and the manufacturer (and between you and your retailer), the better your odds of negotiating an acceptable resolution when returning computers or other faulty merchandise.

Next Issue: Part III