Page 2 of 2 FirstFirst 12
Results 11 to 17 of 17
  1. #11
    Join Date
    May 2005
    Location
    up on the moors.
    Posts
    33,220

    Default Re: Rugged tablet, or ordinary tablet with a good case ?

    Thanks for the suggestions and experiences.

    I am happy with my standard nav kit of paper charts, laptop, small h/h GPS, AIS, chart plotter, and the archive deck log: all of which provide several independent streams of position input and recording. However, they are all located around the chart table, and within the scenario of a solo trip running into a patch of bad visibility or otherwise losing my clear perception of position, the objective is to find a device that could make it unnecessary for me to leave the tiller and work at the chart table. No radar BTW, and my favoured Toughcharts are difficult to use when steering and are passive re position.

    Hence portability, and perhaps links to AIS on a well-regarded active chart system (e.g. OpenCPN/Navionics).

    A couple of PMs have supported the idea of a standard tablet, e.g. Ipad or Samsung Galaxy, in a tough case. A standard tablet has masses of RAM and other storage, decent screen sizes, and seems capable of handling all the data needed . Apparently tablet nav programs will save the track, so that in the event of GPS disappearing, one has a last known position from which to work - but in real time, not when one updated on the deck log 30 minutes ago.

    So ordinary tablet plus armoured case looks like the best piece of kit for contingency, active, position fixing - subject of course to the known vagaries and eccentricities of little chunks of electronics rushing around some 12000 miles above the sea surface.

    Thanks again.


    PS. At the last count I had 4 anchors on board, and some 250m of chain and rope just in case I need to stop and think...
    Last edited by sarabande; 24-06-19 at 10:03.
    I think, therefore I am. I am, therefore I sail.

  2. #12
    Join Date
    May 2007
    Posts
    36,763

    Default Re: Rugged tablet, or ordinary tablet with a good case ?

    Quote Originally Posted by sarabande View Post
    Thanks for the suggestions and experiences.

    I am happy with my standard nav kit of paper charts, laptop, small h/h GPS, AIS, chart plotter, and the archive deck log: all of which provide several independent streams of position input and recording. However, they are all located around the chart table, and within the scenario of a solo trip running into a patch of bad visibility or otherwise losing my clear perception of position, the objective is to find a device that could make it unnecessary for me to leave the tiller and work at the chart table. No radar BTW, and my favoured Toughcharts are difficult to use when steering and are passive re position.

    Hence portability, and perhaps links to AIS on a well-regarded active chart system (e.g. OpenCPN/Navionics).

    A couple of PMs have supported the idea of a standard tablet, e.g. Ipad or Samsung Galaxy, in a tough case. A standard tablet has masses of RAM and other storage, decent screen sizes, and seems capable of handling all the data needed . Apparently tablet nav programs will save the track, so that in the event of GPS disappearing, one has a last known position from which to work - but in real time, not when one updated on the deck log 30 minutes ago.
    .......
    I think it would be interesting to run through how your methodology is going to stand up in a few different scenarios:

    1) You realise you do not trust your tablet's GPS position, but you're unsure when it ceased to be valid.
    2) Your tablet becomes unresponsive at a key moment
    3) You have no reason to doubt the tablet but the indication from the depth sounder does not tally with the chart.
    4) You make somesort of simple basic mistake, e.g. a waypoint entered wrongly.
    ISTM that PhillM's incident showed that having multiple backup devices is no good if you don't have a rigorous method in place.
    It's all easy while everything works as it should.
    When things go wrong and you are tired, how do your methods get you reliably back on track?

    Having sailed some OPB's where people are using such methods, I still think it's good to stop playing with the sails and tiller every hour/30 minutes/(according to circumstances) and put a cross on the chart and do a reality check.

    I'm not really trying to criticise phones or tablets, but trying to look behind that, fundamental methods, what goes wrong, what makes the difference between a comedy moment and a fiasco or crisis?

  3. #13
    Join Date
    Jul 2018
    Location
    Chichester
    Posts
    29

    Default Re: Rugged tablet, or ordinary tablet with a good case ?

    I use a Lenovo Tab 8 Android mounted on a Rokk Midi which is attached to the bulkhead via a Rokk self adhesive mount. The suction cup was hopeless. I've attached a GoPro self adhesive mount to the tablet itself to tether it to the base in case it slips out of the jaws of the Midi clamp.

    It is housed in nothing at all in most of the condition I sail in. If it gets rough / raining it goes in to an Overboard waterproof bag which fits in the Rokk clamp and is again tethered to the base. The screen is still touch sensitive whilst in the bag. I get about 10 hours continuous use on full brightness and yes, it is viewable in daylight.

    This set up allows me to view the screen from the tiller in all weathers and was very handy when caught in fog recently.
    Last edited by Benny257; 24-06-19 at 11:37.

  4. #14
    Join Date
    Jun 2008
    Location
    Surrey and Gosport UK
    Posts
    1,528

    Default Re: Rugged tablet, or ordinary tablet with a good case ?

    My only concern with tablets is the inability to show AIS via Navionics directly (leaving aside the sunlight viewing issues)but its a great back up to a chartplotter ,has its own power and can be backed up by a powerpack plus obviously usual charging via USB or sockets and when paired with the plotter a much more useful device given portability and screen size than say a handheld Garmin as a backup .
    Don't think though I would be without the plotter but if the tablet mirrors the plotter screen and also has an independent capability it gives the flexibility of not being tied to the plotter location . Toughbook plotters always look quite pricey and a standard tablet in a case is probably fine unless you are out in extreme conditions

  5. #15
    Join Date
    May 2005
    Location
    up on the moors.
    Posts
    33,220

    Default Re: Rugged tablet, or ordinary tablet with a good case ?

    You are right to be rigorous and questioning but I went through all those in the Assumptions phase. And have done peer to peer review of the protocol with another (professionally qualified) forumite.

    1) You realise you do not trust your tablet's GPS position, but you're unsure when it ceased to be valid.

    Revert to last position of high confidence. In what plane pilots call VFR, I'd expect to correlate with depth, wind and wave direction, fog sound signals, any lights, RDF, DR position etc every 30 to 60 minutes. Deterioration from visual certainty means reducing the time interval and looking for secondary points of information. The more Venn circles or lines of position you can add, the greater the confidence level.

    2) Your tablet becomes unresponsive at a key moment

    Quick check on other systems. If common source of failure, then stop and think, or if VFR still active, then pilotage not navigation. Or park the boat.


    3) You have no reason to doubt the tablet but the indication from the depth sounder does not tally with the chart.

    If depth is a critical data correlation, then lead line (old diving weight and 15m of best string, kept in cockpit locker. Tide heights and times marked in chinagraph on cockpit status board.

    4) You make somesort of simple basic mistake, e.g. a waypoint entered wrongly.

    I don't have a automatic steering system via a plotter that uses waypoints. It's all manual. My knowledge of an entered waypoint is that it displays on the electronic chart. In theory I could use three separate systems of electronic charts, plus paper. That limits the degrees of freedom for making errors, especially if a waypoint ends up displaying on land or in the middle of Biscay. More of a planning issue than IRL, perhaps ?


    ISTM that PhillM's incident showed that having multiple backup devices is no good if you don't have a rigorous method in place.

    That's the aim. I have identified one particular scenario where my present kit might present a management difficulty, and adding a tablet means the data hitherto available only at the chart table becomes accessible to hand at the tiller. If that system fails (and I think that anyone would perceive it failing within a few minutes,) I revert to heaving-to or anchoring till the prob is resolved.

    It's all easy while everything works as it should. When things go wrong and you are tired, how do your methods get you reliably back on track ?


    I am not being facile about this. I have identified one scenario with a medium risk/high consequence value. Taken in conjunction with the ordinary sensible and experienced practice of seamanship, it seems to me that a tablet is the appropriate response.

    I'd like to think that having worked and taught in the nuclear crisis industry for two decades, I would be familiar with fatigue recognition and management. I also remember the famed Admiralty instructions for dealing with a lee shore. "Don't get caught on a lee shore". Mitigation, mitigation, mitigation.
    Last edited by sarabande; 24-06-19 at 12:13.
    I think, therefore I am. I am, therefore I sail.

  6. #16
    Join Date
    May 2007
    Posts
    36,763

    Default Re: Rugged tablet, or ordinary tablet with a good case ?

    Food for thought, thanks.

  7. #17
    Join Date
    Jun 2007
    Location
    Oban
    Posts
    1,768

    Default Re: Rugged tablet, or ordinary tablet with a good case ?

    In my hands (which may be poor hands) paper methods probably ten times more prone to silly errors than electronic methods. You don't "enter waypoints" you plonk them down exactly where you want them. I propagate routes to at least three, sometimes four devices - this can take up to five minutes of my time. I have, at a minimum one laptop, two android devices and (if I remember correctly) four handheld GPSs that can store all the details. I have had about half a dozen equipment failures in twelve years of sailing this way, and have never had two devices fail at once. When navigating with paper I have on many occasions put the cross in the wrong place - I guess I'm just a bit incompetent.

Page 2 of 2 FirstFirst 12

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Latest YBW News

Find Boats For Sale

to
to