• Welcome to ScubaBoard

  1. Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

    Benefits of registering include

    • Ability to post and comment on topics and discussions.
    • A Free photo gallery to share your dive photos with the world.
    • You can make this box go away

    Joining is quick and easy. Login or Register now by clicking on the button

Algorithms, Conservative Factors, Altitude, Planned Deco - Questions

Discussion in 'Computers, Gauges, Watches and Analyzers' started by CandiveOz, Oct 19, 2018.

  1. CandiveOz

    CandiveOz Barracuda

    Scubapro and Adaptive based algorithms
    Scubapro/Uwatec’s history with the ZH L8 ADT algorithm has been in use for over 20 years or more and is still in use today. The number of safe dives conducted over the decades with this algorithm is testament to its safe record (taking into consideration the surface interval issue with Uwatec’s nitrox version back in 1996).

    Scubapro has recently upgraded to ZH L16 ADT simply because the computers today have more grunt and memory to handle the calculations. To date, Scubapro is the only manufacturer to offer bio feedback or “human factors” to adjust the algorithm in real time. A gimmick or not; it’s an interesting proposition. I think divers refrain from using this technology because they don’t understand it or don’t believe in it.

    Part of the problem is Scubapro itself. In my opinion, Scubapro hasn’t really taken the initiative to address divers concerns and explain in detail how the technology really works. I had a number of questions regarding the Scubapro computers but there is actually very little literature I could find regarding their ADT or Adaptable computer. Unlike Suunto, their proprietary algorithm is in a black box. I’ll continue my investigation into this technology to discover more.
  2. CandiveOz

    CandiveOz Barracuda

    Shearwater and gradient factor based computers
    Shearwater, the darling computer of Scubaboard. Divers on this forum just love this company and its offerings. I’m impressed with the loyalty. My original question to Shearwater users on this forum was about the future. The following comments caught my attention but not in the way one would think.
    By all reports, Shearwater is a great company but unfortunately it is a one trick pony and may suffer the same fate as Gopro. Gopro produced the best action camera in the market and is still considered the global benchmark for action cameras. But Gopro is suffering financially. It is a victim of its own success. Market price went from a high share price of $86.97 in Oct 2014 to $4.59 today. It tried to diversify its product range by getting into drones but failed. Unlike other camera manufactures, it doesn’t have the product range and depth to grow in other areas. The market has changed, other major camera manufactures are making action cameras, cheaper knockoffs are in the market and mobile phones are competing in this field. People who bought a Gopro 4, 5, or 6 probably are very happy and don’t want or need to upgrade to 7. Sure, there will always be the customers who love the latest and greatest and will buy the Gopro 7 but they are a minority.

    So the question for Shearwater is; what happens when every diver owns a Shearwater? It’s a nice problem to have but in reality, unlike other diving manufactures, it doesn’t have a diverse product range which can continue to contribute to the bottom line. Shearwater’s competitive advantage is customer service. It’s not hardware because it can be copied (it currently is) and its not its algorithm because the software is open source. Any programmer worth his/her salt can replicate it (Garmin, Suunto and Scubapro have). The other manufactures are not sitting idly by. In the past, divers thought deep stops were needed; manufactures responded and offered it in some form or another. Now gradient factors are the new thing – easy. Look at Garmin’s offering; a dive computer in a smart watch. Shearwater doesn’t come close in terms of functionality for the recreational sportsman who also dives. My guess is the next Garmin will have integrated air and its offering will be so much more than Shearwater. Garmin’s history with GPS and heart rate monitoring puts it ahead of the curve. In fact it could step on Scubapro’s “Human factor diving” toes. Suunto is in the same position and has a similar history to Garmin. It has followed suit and introduced ZH-L16C with gradient factors as an option in addition to RGBM in the EON Steel. While this will impact Shearwater, Suunto’s key strategy is not to lose market share to its main competitor; Garmin. Also Scubapro announced the Galileo HUD (Heads Up Display). It to offers ZH-L16C with gradient factors along with its standard ZH L16 ADT MB PMG. The HUD will also offer GPS for surface navigation (entering Garmin's domain). I suspect Scubapro will offer a future software upgrade to include gradient factors to its flagship G2 wrist computer.

    My advice to Shearwater is don’t get greedy and maintain its loyal customer base with continued refinements and customer service. If Shearwater does this, it may be able to lock in a niche market for themselves and continue their success. :)

    Attached Files:

    • HUD.pdf
      File size:
      3 MB
  3. KenGordon

    KenGordon Rebreather Pilot

    I don’t think you can compare Shearwater to GoPro.

    GoPro grew enormously with the market for action cameras and once that was exhausted/cheap competition turned up suffered. Shearwater is growing in a mature market using the product itself to gain customers. Also it is more diverse than it looks, all the rebreathers other than AP and Posideon use their electronics, that drives further sales for backups, and provides marketing credibility to the products.

    The whole market is too small to interest those making 10s of millions of 99USD GoPro clones people buy on a whim. The various other manufacturers such as OSTC and LightForMe have not got the traction in the US that Shearwater has. It surprises me that OSTC don’t have US distribution as they have some very good products, although their naming scheme confuses me.

    While on paper the Garmin, Teric and the Suunto D5 (or some yet to be made trimix version) might seem similar they are optimised differently. The Teric screen is much much nicer than the Garmin one, so even with AI and CCR support you’d have to really want the sport watch features or the battery life of the Garmin to prefer it. The D5 has a more mid range feature set than the Teric, but also a more mid range price point. I have not seen the screen, so maybe it will be a challenge.

    It will be interesting to see how the Eon Steel goes with ZHL16 & GF. I no wonder slightly regret not buying one when the BSAC instructor deal was running, but of course the same logic applies as for preferring a Perdix over an OSTC, I want the same UI on both my RB computer and my backup. I would like Shearwater to improve the CCR, and especially bailout, features of their computers though, rather than messing about with wild Time To Death by Drowning (TODBD (tm)) features for people who don’t plan their gas. I suspect they outnumber the CCR users 50 to one though.
  4. KenGordon

    KenGordon Rebreather Pilot

    Wrt Scubapro doing ZHL16, again it will be interesting, but mostly that only really matters to people who want two computers to match or want to plan with Multideco. If Suunto or Scubapro did iOS/Android planners then ZHL16 would be a less useful feature. The actual algorithm is secondary to the rest of the features of a computer. I know this is herasy in SB terms, but really they all do more or less the same thing plus or minus a couple of minutes.

    I expect the marketing departments at these companies have been reading SB and twisted the arms of the development departments to be able to tick the box.

    I’d like to see how aggressive you can set them.
  5. CandiveOz

    CandiveOz Barracuda

    Hi @KenGordon thanks for adding some balance to my Shearwater review. I’m not a rebreather diver so I didn’t realise they had a virtual monopoly in this market. And as I have indicated, if Shearwater play their cards right, they should be fine.

    In general, the future of dive computers will be interesting over the next 5 to 10 years. In terms of form factors; within the next 5 years, I believe all new computers on offer, from Rec to Tec, will be colour screen based – even the base models. The wrist mount with wireless air integration will grow in popularity, with demand for hose based air integration falling due to the fact that a wrist mount with wireless air can be worn on the arm or clipped to a retractable cord on the BCD. Smart watches with diving functionality will continue to grow due to their versatility. For the future of heads up display (HUD) it’s difficult to project (pardon the pun). Unlike Smart watches, they are strictly limited to diving and it will really depend on marketing, price and functionality (how good they are) for wider acceptance in the diving community. Another innovation that may be further developed is an ear/head piece that communicates the dive computer statistics audibly. An interesting piece of kit is the Roorka for free divers. Similar technology could be employed for SCUBA divers. All important data such as time, depth, NDL, decompression stops and ascent rate could be relayed to the diver audibly while he/she focuses on the task at hand – even relaxing music could be played while hanging on the deco line!
    roorka.com (EN)

    In terms of algorithms, the current trend is Gradient Factors and the ability for the diver to fine tune his conservative level. I suspect over the next 5 years, all dive computer manufactures will offer this feature as an option or as replacement to their current algorithm. @scubadada made a post on the new Mares Genius.
    Mares Genius
    Mares has dropped RGBM in favour of ZH-L16C with Gradient Factors on the Genius. Scubapro and Suunto are going to offer the same on their flagship models as an optional model. It is only a matter of time for other manufacturers to follow and for GF’s to filter down to the base models.

    It is interesting how Mares has implemented GF’s on the Genius. Of course there will be default GF settings but there will also be a method of adjusting the gradient factors based on the diver’s current physiology (age, weight, fitness etc.), current dive conditions (strong current, deep dive) and personal dive day readiness (lack of sleep, dehydration etc). The gradient factors will also be automatically adjusted for repetitive dives if the surface interval is shorter than 2 hours and reduced for multiday dives. All these adjustments are an attempt to personalise the algorithm to the particular diver on a specific dive or series of dives. It’s another approach to Scubapro’s human factor diving. On that note, I would expect, or hope, that technology would develop over the next 10 years for a chest strap or arm strap that has a mini-ultrasound doppler to measure bubbling during a dive similar to heart rate monitors currently in use today. The doppler wouldn’t replace a dive algorithm but supplement it. The dive computer would collect a diver’s bubble data over a series of dives and use this baseline to apply to future dives. Decompression profiles would remain the same as per the base algorithm, but a stop may be extended to allow excess bubbling, versus the baseline, to subside before proceeding to the next stop or surfacing. Monitoring could continue during the surface interval to ensure bubbles are minimised before the next dive. This technology would take human factor diving to a new level.

    So there are my future predictions on dive computers for the next 5 to 10 years FWIW.:)
  6. scubadada

    scubadada Diver Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Philadelphia and Boynton Beach
    There have been many significant advances made in dive computers, particularly in the technical/rebreather realm. In the rec world, there have been fewer major changes than many might think.

    As an example, Oceanic has offered a wireless AI computer since 1995, 24 years. The Data Trans was air only, used the same PPS transmitter in use today, ran the DSAT deco algorithm, and displayed a graphic air time remaining that included ascent, safety stop or required deco stops. In 1997, the Data Trans Plus added nitrox and added dive time remaining, a numerical display of the limiting variable, NDL, gas, or O2 accumulation.

    Don't get me wrong, I'm pretty sure my next computer will have a beautiful color display and will run Buhlmann ZH-L16C with GF. That is, if my current primary computer, a 8 1/2 year old Oceanic VT3 with 1250 dives and 1,323 hours, ever stops working :)
  7. Saboteur

    Saboteur Regular of the Pub

    # of Dives: 100 - 199
    Location: Earth
    There might be a future market and shops dedicated to vintage single hose diving....
  8. CandiveOz

    CandiveOz Barracuda

    When I started my original post in October 2018, my objective was to upgrade my Tusa IQ750. I started to review the different computers available today to gain a better understanding so that I could make an informed decision regarding my upgrade. I had a whole bunch of questions that needed answering so I posted them on this forum hoping members would help me out. And boy did they ever! I learnt so much from everyone and am so grateful for the time and effort divers put in to help answer my questions. Particular thanks goes to @Jay_Antipodean, @scubadada, @KenGordon ,@dmaziuk, @stuartv, @Diving Dubai and @lv2dive who was the first to kindly offer advice.

    Of course as the months passed by I started looking for a replacement dive computer. My main requirement was a wrist mount air integrated computer. I couldn’t justify buying a new so and I made a challenge for myself to spend under $500 AUD for the entire kit. Here is a summary of my purchase journey.

    My first bid was on a Suunto Vyper Novo with a AI transmitter. The seller was also offering a Cobra so had two computers to sell. I liked the Vyper but the price was too high at $650. I could by a new unit with full warranty for $765 so why would I buy a used one for only $115 less. I offered $475 which I thought was fair and more than half retail price but in the end we could not come to an agreement.

    My next attempt was on Ebay. A Shearwater Perdix was on offer without a AI transmitter. I decided to put in a bid knowing it was highly likely to sell higher than my budget (maybe I would get lucky). But it did at $610. Next up was a Mares Icon with transmitter. Not as popular as the Shearwater and a number of Scubaboard members commenting on the short battery life and difficulty reading in bight sunshine. I thought I could live with that with my type of diving. Again I missed out since the unit sold above my budget.

    Finally a brand new Aqualung i750 with colour display was on offer; apparently an unwanted gift. Again comments on Scubaboard indicated short battery life and difficult reading. But if the price was right I would still go for it since it had the same algorithm as my Tusa so they would closely match on dive profiles. It didn’t come with a AI transmitter, but I thought I would have some budget left over to contribute to a used one. I actually won the bidding at $349! I sent the seller the money through paypal and waited for delivery. The next day I received a refund on my paypal account with a note from the seller that he had already sold it offline. I’m not sure if that’s kosher with Ebay rules but I let it go. Maybe just as well.

    Finally I found a seller offering a Scubapro Galileo Sol with heart rate monitor and AI transmitter for $750. Apparently it was hardly used since purchased (14 dives). When the seller took up diving, he had grand ambitions of becoming a dive instructor so he bought all the top gear at the time. He eventually lost interest and the Galileo was sitting on his bookshelf collecting dust. I offered $450. After some texting, he came down to $550. I offered $475. Again more texting, he came down to $500. I held firm at $475, indicating that it was my final offer and if he wanted sell at a higher price I’m sure there would be buyers out there. I thought that would be the end of negotiations but he kept contacting me. Eventually we cut a deal at my price of $475.

    Sure enough, when I picked it up, it looked brand new. He never used the heart rate monitor so it was still in its original wrapping. I’m very happy with the purchase. The unit has a great big display which I like, the batteries in both the computer and transmitter were fully charged and the heart rate monitor is something I want to investigate further. Now I’ll be able to play around with the unit and get some definitive answers to the questions I had about Scubapro dive computers and their “human factor diving.”
    scubadada, Jay, Diving Dubai and 2 others like this.

Share This Page