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3 divers missing off of Java

Discussion in 'Accidents and Incidents' started by whysocold, Nov 4, 2019.

  1. nippurmagnum

    nippurmagnum Barracuda

    # of Dives: 500 - 999
    Location: Washington DC metro
    224
    210
    43
    I bought a Nautilus Lifeline for $170. Has a user-replaceable battery, and can be reused to your heart's content. Sends a beacon to any ship within 30 miles, anywhere in the world.

    When I mention that I carry one on liveaboards in areas with current, most people's reaction is "I'll stay close to you then."
     
  2. Dan

    Dan Orca

    # of Dives: 500 - 999
    Location: Lake Jackson, Texas
    5,666
    3,201
    113
    Good for you. I think 30 miles if the boat has very tall antenna and smooth sea surface. “Normally, an AIS-Receiving station using an external antenna placed 15 metres above sea level, will receive AIS information from AIS-equipped vessels that sail within a range of 15-20 nautical miles”, https://www.google.com/amp/s/www.al...asics-epirb-ais-plb-pab-whats-difference/amp/

    “Typically, a VHF transmission from a ship with it's antenna array at 100' above sea level will be picked up by a pulpit mounted antenna at 10' above sea level at a distance of 16 miles. Smaller ships will have an antenna set somewhat lower, say 40 -50', and this would drop the range to 12 miles.”, AIS range issue... [Archive] - Yachting and Boating World Forums

    Sticking up your hand at sea surface will get the antenna at about 3’ (1m) and surface condition would bring the range down to may be a couple of miles.

    So, I’d suggest you to get a PLB also.
     
    tridacna likes this.
  3. nippurmagnum

    nippurmagnum Barracuda

    # of Dives: 500 - 999
    Location: Washington DC metro
    224
    210
    43
    So help me out -- the Nautilus Lifeline claims a range of 34 miles: Nautilus GPS Features & Specifications - Nautilus LifeLine

    It also claims to be a PLB.

    Are their claims wrong? I bought the unit based on the recommendation of another diver I met on a liveaboard who used one in an emergency and said it definitely worked.
     
  4. Dan

    Dan Orca

    # of Dives: 500 - 999
    Location: Lake Jackson, Texas
    5,666
    3,201
    113
    I carry one in all my bluewater diving too, as shown in my earlier posts. As mentioned in my earlier post that 34 mile range depends on surface condition and line of sight. With swell, earth curvature, and object in between the transmitter and receiver, and the strength of the signal, that range would be diminished as mentioned by the users.

    It is not PLB either. PLB uses 406MHz signal directly to the SAR satellites. This Nautilus device uses VHF radio signal to transmit MOB (man overboard) via DSC, Digital selective calling - Wikipedia & AIS which both signals are based on VHF radio. That is why it is called PAB, not PLB. It’ll get the GPS location from GPS satellites though.
     
  5. Dan

    Dan Orca

    # of Dives: 500 - 999
    Location: Lake Jackson, Texas
    5,666
    3,201
    113
    Another news:
    “A total of seven foreign tourists went out diving in two groups, but the missing trio - one Singaporean and two Chinese nationals - did not return to base.”

    Singaporean among 3 missing while diving in Indonesia

    This latest news sounds like the diving was not guided by a local DM and venturing in the area that is known for strong current.

    The link, above, also provides a better map of the area, as shown below. Anak Krakatau means Sons of Krakatoa, which are the rim of Krakatoa crater raising from the sea after that volcanic mountain blown off in 1883, 1883 eruption of Krakatoa - Wikipedia

    603519A3-62D0-4813-B165-F27F35A1E27D.png
     
  6. RogueClimber

    RogueClimber ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 25 - 49
    Location: Honolulu
    71
    51
    18
    Their wording is precise so they can make such claims:

    "a man overboard distress message will be broadcast to all AIS equipped ships up to 34 miles away"

    Up to. So in the absolute best conditions they were able to broadcast 34 miles.

    And they actually say:

    "The Nautilus LifeLine Marine Rescue GPS is more than a PLB"

    So they are not claiming to be a PLB (which they are not)
     
    Dan likes this.
  7. nippurmagnum

    nippurmagnum Barracuda

    # of Dives: 500 - 999
    Location: Washington DC metro
    224
    210
    43
    So what is your estimate of how far their effective signal would reach?
     
  8. Dan

    Dan Orca

    # of Dives: 500 - 999
    Location: Lake Jackson, Texas
    5,666
    3,201
    113
    “Personal AIS Beacons (PAB): These new devices gained FCC approval for use in the U.S. in April, 2012. Personal AIS Beacons are intended to be attached to your life vest and activated if you go overboard or encounter some other emergency while you’re in a dinghy. They use both GPS and AIS (Automatic Identification System) technology to send structured alert messages containing your precise location information to any AIS receiver onboard your vessel and to other AIS-equipped boats or ships that happen to be within a typical four-mile radius. In a crew overboard situation, chances of finding and recovering the casualty are greatly increased, thanks to information given by the PAB, which for the first time shows bearing and distance to the person in the water.”

    Selecting an Emergency Beacon | West Marine
     
  9. Dan

    Dan Orca

    # of Dives: 500 - 999
    Location: Lake Jackson, Texas
    5,666
    3,201
    113
    “...As Galih and his fellow rescuers set off on Thursday morning, they faced unfavourable conditions, with high waves and strong winds hindering the search.

    Galih told The Straits Times in a telephone interview during his break that Indonesia's search-and-rescue agency (Basarnas) will continue operations till the seventh day, before deciding on a future course of action.

    If the rescue team find any clues in the waters, such as personal belongings or diving equipment, the search may be extended, he said.

    "The divers' families attend our evaluation meetings every night before returning to their hotel. They are naturally worried and afraid about their loved ones. We have to try our best and stay optimistic about finding the victims," he added.

    At least 12 vessels, including navy ships and police patrol boats, as well as two helicopters have been deployed in the search that covers a total of 1,300 square nautical miles. A diving unit has also been activated to comb a designated zone within the search area.

    Working from 6 am to 5 pm each day, Galih and other pilots search an area of about 922 square nautical miles. The area covered by air operations is the biggest of the four regions covered by the entire search team....”

    https://www.google.com/amp/s/www.th...ver-and-2-others-hampered-by-bad-weather.html
     
  10. nippurmagnum

    nippurmagnum Barracuda

    # of Dives: 500 - 999
    Location: Washington DC metro
    224
    210
    43
    Good to know, many thanks.
     

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