Future of Sonar

One of the most interesting (and maligned) parts of the Descent MK2i is the sonar connection to the transmitter. Obviously some people hate this system because it's proprietary or they notice a sound from the transmitter. One of the best things about it though is connecting to another diver's air as well as your own. My gf is a new diver, and I bought a second transmitter just so I can keep an eye on her air, we have yet to use it, but I am looking forward to seeing how it works. I trust her diving, and maybe it's just the nerd side of me enjoying having more data... but I also like the idea that I can keep an eye on her air.

So what else can be done using this sonar tech? It seems like a lot of potential. Maybe instead of just seeing your partner's air, you can see their NDL time too? Or get alerts when they are close to NDL or other limit? What would be really cool is a way to communicate, or at least send an alert to your partner... something like the old "Buddy Watcher" system. I could see where if my buddy sees something cool they could select to alert me of it... or there could be an emergency alert system too. 

Obviously the interface for this would be important. You don't want to confuse the NDL of your partner(s) for your own. I also don't want to get an alert every time they ascend too fast... unless it goes on for 30 seconds... or some other user selected time. The communication should be intuitive and non-invasive. Perhaps a double press on a button sends a "hey, come look at this" alert to your partner, and a long press sends a more emergency style alert to everybody in the area.

Does the technology have the capability of locating someone? Scubaboard is full of "diver lost" situations. Maybe the ability to ping your partner could yield a direction and possibly distance?

  • I have a similar setup as you where I have 2 transmitters for my wife and myself. As you enjoy the nerding out you can send any information you want the question is will it be relevant. I could see something like low air, but you can set that feature in the Mk2i setting (I have mine set to our turnaround point). A quick message system would be nice however I don't see how just the transmitter end sends messages. I understand the person wearing the watch could send tones like achievement unlocked sound when finding something interesting or an end of world tone when danger is close.  Locating a lost dive I have a few thoughts below. 

    I don't know if this would be possible the main reason being how distance devices work underwater. However, I have some knowledge in Aircraft Aviation Navigation and Communication systems, I also have knowledge within the IT industry. Giving all the knowledge that I have acquired over the years this is my two cents.

    First, let's get on the same page and discuss the issue of a reference point. Yes, the Garmin Watches have the compass built-in, the problem comes into play while maneuvering during the dive the magnetic fields shift depending on your directions. The second part of the issue would be how strong of a sensor is to receive the magnetic baring and making sure the placement is the same every time while gathering a reading.  That's why while navigating underwater there is meant to be a designated navigator. The second issue is how to reliably send the information. 

    My thought is to have an accessory that can be added to the BCD or 1st Stage. Inside would be a mechanical gyro with a compass in the center (kind of like the old ship gyrocompass). This would allow a member to do all kinds of flips in the ocean and the magnetic heading would not change. This could save members as well in the event their dive buddies if they were unconscious. The second would be using the barometer to see how deep each member is and calculating the differences (+1.3' or -4.2'). This would give us a heading between each member and their current depth. The final would be distance and this could be done by adding a time during transmit and received time. All these factors put together not only would be good to find/track your dive partner but also allow Garmin to do a navigate home feature. Once we have the start reference point and current location a triangulation home would just find the difference between the two compass headings (with duration). This would provide an "as the crow flies" navigation home.

    Take away, aircraft have been known to use laser ring gyros to find/calculate their navigation the issue resides in two independent sources to find a common point and determining their location from there. However ever since we never start a dive at the same location and GPS has an error rate that needs to also be calculated since (accurate of up to 3'). My other thought is that Garmin can make a  dive HRM that would work during the dive and incorporate this idea.

  • I don`t believe that the computer itself is able to send signal, its a receiver. The transmitter does not know anything apart from pressure so al calculations could be only done in the receiver side.

    We already have solutions for most of the problems.
    The compass (analog and digital) is perfectly fine for navigation underwater, no need to reinvent the wheel.

    For communication, there are hand signals, wet boards and loud tick in your tank.

  • Yeah, I know the current hardware won’t support any of these new ideas, but future hardware could easily. While we certainly have current solutions for communication, I would welcome some new ideas.

    We already had a solution for reading tank pressure before we had air integrated computers… but they offer some advantages. Pinging your partner quietly without looking has advantages too. Having an ability to get direction and distance to someone or something can also be really helpful in low vis situations or emergencies. The reason Garmin went with sonar rather than the already proven transmitters is because it opens up more opportunity. I don’t think that opportunity should be limited to just reading multiple tanks.

  • Some other manufacturers already did text message sending to another diver. I cannot recall the brand, but it was a couple of years ago.

  • I think the computer/watch would be able to send information. I have not found anything that states either side of this topic however I believe it could. The main reason is that the watch is able to make sound as it is, all that need to happen is to have the watch generate a sound at a audible level another watch could pick up. Then its just as simple as packaging the message so instead of reading tank PSI it reads the message. 

    The compass does work, my reinvention of the wheel is meant to aid not only in the event of emergency but also when you have a buddy that cant read their compass and end lost. Who knows adding an attachment to a boat or a anchor point can aid in navigating and reducing the need to surface to find the boat or way back.

    Communication is vital for all dives, adding another form can ensure safer and more enjoyable dive :D. 

  • The idea of a gyro type device for dead reckoning is a great idea, usually theyre quite large so ideal for boating, not sure how practical for diving, with diving you know where youre entering or exiting and you should have some cardinal orientation from subsurface geography to eyeball place and position, if your swept out to sea youre going to need other tech like plb to help you get back

    For night diving some sort of tracking would be useful and the sonar signal on the tank pod, or other sonar generator, would be a good idea maybe an additional screen on dive screens for direction and strength of recieved signal, but 10m is no distance at all for that sort of thing unless in distress signal can be increased like if trapped or out of air, thats a good practical idea