NOTE: WRITTEN A LONG TIME AGOAladin Air X ComputerIf you ask me what piece of dive equipment I own has most disappointed me, I think that I would have to answer "My Aladin Air X dive computer". Why? Well, while it has some fantastic features, it appears to be badly made and prone to breaking down, either temporarily or permanently. Some explanation.In about 1990 I purchased an Aladin Pro dive computer. This served me perfectly well except for the occasional time when it kept running when left in a damp environment. This was a marked contrast to the previous Aladin computer which had a lot of problems. The only real problem I noticed with the Pro was that in some cases (mostly when used by a diver who did less than 50 dives a year), the battery warning did not work and instead the computer went haywire, showing a dive just completed as being done to an enormous depth (eg 96 metres). A new battery solved the problem. Even disconnecting and reconnecting the battery solved the problem temporarily (this was like rebooting a PC).In late 1994 my house was broken into and amongst other things, the Aladin Pro was stolen. I decided to use the insurance money (as well as a considerable amount of my own) to upgrade to an Aladin Air X. This cost, including DataTrak software and connecting cable, was about A$1300 (US$845 at the time). Even though I knew there had been a lot of problems with the early examples of this new computer (it had by then been out over a year), I thought that the bugs would have been ironed out. This was not to be the case. I got the computer in February 1995.My first use of the computer was in Papua New Guinea on my 804th dive. I had also purchased the software and downloading cable and my first attempt to use it failed miserably. Even phone calls to the Australian distributor failed to solve the problem so I lost all my data from that trip. The problem appeared to be that the software was incomplete or faulty. I should point out at this time that I work in the IT (computer) Division of a large NSW Government Department so I think I know what I am talking about when I say the software was faulty.When I arrived home, I called the distributor again and attempted to get the problem resolved. I convinced him to send me another copy of the software and once I got this, the download feature worked perfect (well almost, see my later comments about the limitations of this software).Over the next year and a bit it worked okay (see comments about when it did not). The computer's integration with the air pressure in my tank was a marvellous feature and very handy when doing deep decompression dives (which I do often). In addition, the lack of a normal pressure gauge and attached hose meant that there was less to get caught up on rocks and wrecks. The location of the pressure gauge on the computer meant that it was also a lot easier to keep track of your tank level as every time you look at the computer, you should see the amount of air left in your tank. In addition, the ability to download the dive data from the computer to a PC and print this out meant that I ended up with a good record of the dive (the software had limitations and even now it is not real good).However, every now and then the computer did not switch off after diving or it restarted diving by itself. At these times, it seemed to sometimes be caused by being kept in a damp environment (eg in a dive bin) but at other times there was no obvious reason for the action. When this occurred, it meant that you could not download the dive data nor could you use the computer with any degree of accuracy. When it did this, it nearly always went into altitude mode (you can tell this as the deco stops are at 2 metres rather than 3 metres) and the depth at the surface was about 1.4 metres. The computer kept running as if it was completing one huge dive and while you could use it on a dive, it meant that the computer was over conservative and cut your bottom time dramatically (since it thought you had already been diving for hundreds of minutes). Eventually, the computer would reset itself and work okay.In early June 1996 after exactly 150 dives (my 954th dive), the computer died totally and started leaking oil from the screen. The computer was replaced under warranty even though it was four months out of warranty. The replacement computer was exactly the same, it still occasionally kept running after the dive. It even did it first dive after I got the replacement!!In November 1997 when diving in Chuuk Lagoon, the computer started giving funny tank readings. I kept complaining that I was getting really poor air fills but I still seemed to be not using too much air. Finally, on one dive (my 1,130th dive) I noticed that even after I had been in the water for a considerable time (at 50 metres), the tank pressure was higher than I thought it should be. Even after more time, the pressure had not dropped too much more so I knew something was wrong. Luckily I am very good on my air and had plenty to spare. Despite this, I finished the dive (after a lot of extra deco) with the gauge showing 60 bar but the tank empty! A bit of a problem.As I normally do, I had a spare pressure gauge with me so for the rest of the trip I used both gauges. Eventually the Aladin Air X stopped showing the tank pressure.I should say that at this time I knew of at least six people who had at least two Air X computers after their first had failed. Some had had more than three replacements but this was the first transmitter I had heard of failing.Upon my return to Sydney, I took the computer to Uwatec. I was given a new transmitter for the sum of $90 (especially note this price for when you get later on in article) which was said to be the cost of a new battery.After this the computer did not have a major malfunction for two years and ten months (more about this later) but it had the altitude/diving problem at least seven times. In January 2000, it had the worst attack of the altitude problem yet. At 0309 on 1 January 2000, a friend rang my mobile phone to wish me a Happy New Year (thanks Maret!). My mobile was next to the Air X. The next morning, the dive computer was showing a depth of 1.4 metres. We went diving and the computer showed a reduced bottom time (since the computer had already been diving for over seven hours) than my buddy. The second dive was even worse, with the computer going into decompression well before it should have.Normally I would have expected the computer to fix itself by the next morning but it did not. On 2 January I went diving again, with a spare computer. The reaction from the Air X was similar to the day before, with reduced bottom times. After the first dive I cleared the deco but at the end of the second dive it still showed eight minutes at two metres. I declined to do this since I had already done a 10 minute safety stop! The computer did not surface but stayed at 1.4 metres and beeped like hell. It stopped after a few minutes. The next morning the computer had reset itself and appeared normal, with no alarm showing. We went diving again. As soon as I hit the bottom, the remaining bottom time was only 8 minutes whereas it should have been about 25 minutes. Funnily enough, it never got much worse and even at the end of the dive there was still an indicated 4 minutes bottom time. However, my buddies computer showed only 2 minutes. After the dive, the desaturation time was over 70 hours. Considering that even when diving the SS President Coolidge, doing two deep dives a day, I have never before got over about 30 hours. Before the next dive the "Attn" signal came on but I ignored it as I was not using it as a computer, just a pressure gauge. The next dive was similar, with a small bottom time at the start but not much change throughout the dive. The desaturation time was still around 70 hours.However, once I downloaded the computer, the graph for these two dives was totally different to that shown during the dive. The microbubble signal was at its maximum during both dives and on the second, it showed decompression of 56 minutes was required! However, this not signalled during the dive?The "Attn" alarm remained on the computer for the whole 70 hours desaturation and but then worked okay for the next nine months.On 16 September 2000 on the 508th dive using the replacement computer (my 1,466th dive), while diving at Barrens Hut in Sydney, I started my ascent. At about 10 metres, the computer suddenly went blank and then came up with "Err" appearing in the bottom left of the main screen. Almost two weeks later it had still not corrected itself and appeared to have died. It should be noted that the battery life was still between 30 and 40% so it should not be this causing the problem. On 29 September 2000 I again took it back to the Australian Uwatec distributor. After looking at the computer, an employee of the company explained to me that they did not actually do any repair work on the computers in Australia and that they are all sent back to Switzerland (this I already knew from other sources). He told me that since it could not be repaired here, Uwatec's policy (and I took this to mean the parent company's) was to provide a new computer for the cost of repair . He also told me that it was not an uncommon problem for Air X computers to fail, hence this policy. He then set about getting me a new computer and processing it. I was out of there in ten minutes or so, less A$195 (incl GST) and with a new computer. Not too bad I suppose considering the battery was less than 40% and the strap would have needed replacing soon. I first used it on dive 1471.On 6 July 2002 after a slight knock, the strap broke. The plastic ends where they join the main body are very flimsy and one of the segments broke along a joining pin. I took the computer to Abyss Diving in Sydney and they sent it off to be repaired. Imagine my surprise the next weekend when I went to collect and I found that it was repaired and there was no cost! On 20 April 2003, on my 1,861st dive, the transmitter suddenly failed during a dive after having worked earlier that morning. This meant that the transmitter had lasted 730 dives since it had been replaced about five and a half years earlier. The Operating Manual says that the battery in the transmitter should last about 8.5 years based on the average of 132 dives I have done each year since late 1997. Therefore I should have got about another three years service out of the transmitter. The distributor said that it was probably not the battery and that the transmitter had failed. After some discussion about the problems I have had with the computer and transmitter over the years, I got a free replacement transmitter. I did not use this at first as I had another one that a friend gave me when his dive computer died and he switched models. I used this till dive 1972 when it died (this lasted almost 10 years from new). I used the new one from dive 1,973. I now have a dead transmitter (as well as a functioning one) and I intend to attempt to open and replace the battery. I have nothing to lose.In late-May 2003 (after my 1,869th dive), almost almost three years (32 months actually) after my acquiring my third Air X I wrote that it appeared to be working okay. In fact, I had not had a problem with it at all on or after any of the dives I had done using it. At that time, the battery level was 61% (having dropped about 10% in the previous 10 months - 102 dives). Note that this was far better than the last computer which was less than 40% after 500 dives, so I was getting about 100 dives for 10% of battery (compared to 77 dives per 10% on the last computer). I had calculated that if I would get another 50% of the battery life out of it, I would get about another 500 dives or another 3.5 years or so. This would give a total of 900 dives from the computer and say six years ownership. This is marginally more than shown in the Operating Manual.However, on 16 May 2004, the computer died while diving Shiprock. Again, as 16 September 2000, the screen went blank and came up with "Err". This was my 1,986th dive, meaning it had lasted 514 dives (discounting one dive when I did not use), only six more than the last one. Once again I was forced to approach the Australian distributor, now owned by Scubapro but still run by the same person. However, this time I decided to bypass this person and spoke to two other people. Both advised me that the problem would be the battery was dead. I asked why then did the computer show that there was still over 50% battery and one person claimed that the battery level indicator did not actually show the remaining battery level, but recorded the usuage and deducted this from some amount.During discussions in April 2003 it became apparent to me that although the battery can be replaced in the computer (according to the manual), the distributor does not do this and the computers are sent back to Switzerland for repair/battery replacement/refurbishment (note that in 2007 they said that the Air-X could not be opened without breaking the case). Instead, they provide either a replacement Air X ($195) or a new Air Z ($395), although the first option is not always provided unless you insist. This was not offered to me, I only found this out later.At the time I understood that the reason the battery could not be replaced is that the insides of the computer are enclosed in some sort of "oil bath" and that the whole thing needs to be opened when enclosed in oil. Note what happened to my first Air X, it leaked oil (I had always wondered why this happened). In addition, although the battery in the transmitter can apparently be replaced, it is not done unless you insist and instead a new transmitter is supplied for $249. These represent extremely excessive costs, having risen over 100% in 2.5 years in the case of the computer (since the Air X option is not offered) and the replacement cost of the transmitter has risen over 170% over 5.5 years. I wish I could get a pay rise of 40% or 31% per annum. My latest transmitter appears to have died as of 1 July 2010. This meant it worked for just over seven years and about 1,040 dives, a good number compared to my previous ones. I will update this page with the price of replacing it once I have done this.As much as I hate the poor reliability of the computer, the inability to replace the battery, the poor customer relations, I am locked into the Aladin AirX/AirZ for one simple reason. To any other computer would cost me over $1,000 and up to $2,000. Reluctantly, I replaced it at that time.So far (as at 25 July 2007), after about 1,720 dives with the computer (and its three replacements and two replacement transmitters), it has cost me a total of A$2,119 ($1,300 purchase price, $90 replacement transmitter and $195 replacement Air- X and $395 replacement Air-Z and battery replacement for Air-Z $139). This works out at A$1.23 a dive. Consider that I used my Aladin Pro for exactly 500 dives before it was stolen and it cost me A$650 (purchase and a battery), $1.30 a dive. Of course, except for the thief, I would probably still be using the Pro which would work out at about $0.31 a dive (assuming another three battery changes done by myself) over the 2,235 dives since then. A bit expensive I think.NOTE: The US Divers' Monitor 4 is virtually identical to the Air X and is also made by Uwatec. It also appears to suffer from the same problems, but since there are far less around, the level of problems are not as easy to ascertain.Some comments on all this. Well, the computer certainly has its faults but it is also, when working correctly, fantastic. First, the pluses, then the minuses.Positive Points