Marine Search and Rescue (SAR)

I'm researching the viability of KAP for marine search and rescue craft. The efficiency of searching at sea is greatly impacted by viewing height above the water. In most fast response rescue boats that may be as little as 6 ft, sometimes less than wave height. If it was possible to get a stabilized video feed from a towed kite, searching capabilities could be greatly improved. In our situation we think a tethered system has specific advantages over drones.
I'm therefore looking for advice since I'm starting from scratch and clearly this community has the experience. It's a challenging environment and may be beyond KAP capabilities, but that's what I need to find out.
Here's the basic criteria:
1) Operation over water in relative wind conditions from 10kt to 40kt (Vessels travel up to 35kts).
2) Heights of 40ft or greater would be good.
3) Live stabilized video stream required for periods up to 1 hour (power available from vessel).
4) All operations, including launch and retrieval, would need to be carried out from the rear deck of the cabin vessel. A powered winch seems a likely requirement. Vessel photo and specs:


  • Let me say that I am one of the less experienced KAPers on this forum. {Really.}

    That said - AND I am JUST GUESSING here - try one of these for a lifter...
  • And...

    {This includes the Helikites I mentioned in my previous post.}
  • I would have thought that a multiple drone operation would be the way forward. With some of the higher end machines capable of 60-70mph, 40 knot winds would not present a problem.

    I discussed this briefly with a local SAR volunteer who told me that they already had an eye on the feasibility of drone use in addition to the lifeboat, RIBs and aircraft assets that are available.

    The ability to hover over a target thus pinpointing GPS coordinates for recovery teams to come must be advantageous.

  • KAP from a fast moving boat, particularly if the KAPer can direct the skipper to adjust speed or direction in order to keep the kite aloft and under control, is certainly possible - see for example here. And stabilising a rig (and hence the video feed) using a gimbal is also possible - see Skysnaps posts here for example. Given the relatively high speed of the kite with respect to the air, you'll need a robust kite like a PFK NightHawk from Paul's Fishing Kites in NZ.

    But, and these may be big buts, I see two problems. First I suspect a lot of your rescue work is likely to be in rough seas and high winds, which makes for an unstable platform to KAP from - skill and experience will be needed. And second, most video downlinks are not high resolution, which may make it hard to spot the things you want to see.

  • Thinking sideways from this, I'm surprised in suitable conditions in the past they haven't parascended crewmen and cameras from search vessels. I can find no references to uses other than sports. As for KAP it could certainly be done in some conditions and one could envisage automated systems and winches for pattern searches that would provide that eye in the sky, perhaps with IR as well as normal spectrum downlink. It's difficult to say, a well designed system might be quite effective. Problem is in the sort of conditions that SAR is normally done in, KAP might be more of a liability than an asset. I think drone technology is now advancing so quickly it would be a backward step to go for tethered systems. I know fire brigades and police are already using drones, I can't imagine the coast guards and Lifeboat organisations and SAR people aren't looking hard at drones.
  • edited April 2017
    An aside, but I remember reading a patent on a kite rescue systems to reach ships stranded on barrier bars in heavy surf. It was a heart-breaking thing years ago to see people die within view of shore in such situations. I think they outfitted some rescue teams with kites, but shipwrecks and conditions never facilitated their use.

    I think for your use things seem to have converged on aerostats or UAVs. Our navy and coast guard have been working on larger versions of these for decades:

    A KAP or aerostat system with full rig control/downlink might be more useful as an observational platform in non-emergency conditions or in fixed locations (life guard duty on busy summer beach?).

    In emergency conditions a tethered kite would add a huge additional headache to whoever was steering the rescue craft. A blimp-like aerostat on a mast might be a bit more resilient to course adjustments. A UAV would be something they could completely forget about when it wasn't taking off and landing.
  • Thank you one and all for sharing your experience and ideas, greatly appreciated.
    As I mentioned in my original post, I have no KAP experience. My thinking was that a hard wire connection might overcome the significant downsides we face with affordable UAVs, namely endurance in high winds and quality live feeds. Simple operation is essential during SAR activities as all crew members are multi-tasking and the "follow-me" capability of some commercial UAVs is ideal if only they could stay aloft longer - this led me to considering KAP.
    Based upon your combined feedback I believe we should test a high wind kite from the vessel to better understand the process and results.
    Dave, I note you identified PFK's NightHawk, any reason for this kite rather than their Super Kite which appears to be rated for higher winds with a smaller wingspan?
    Thanks everyone!
  • Things that pop into my head:

    A PFK with one of those dynamic spreaders would be pretty awesome.

    How do you propose hard wiring? That obviously adds weight and will have an impact on a kite's behaviour.

    I would consider a double camera/live video feed concept: wide angle for general searching (e.g. GoPro type) and a camera that can have it's lens (zoom) controlled.

    If you go ahead and test then you need to ensure that your skipper understands that sharp moves between port and starboard will upset a kite. I learned this the hard way about 8 years ago when my flowform quickly became a sea anchor.

    Weigh up UAV endurance issues against the distance and search area that can be covered by a simultaneous multiple UAV operation. Maybe do some calculations on this front - 1 kite vs 2 or 3 UAVs over an hour. I would assume 3 flights per UAV per hour.

    Looking at your vessel, launching a kite looks like it would be a challenge in stronger winds given the cabin is effectively a wind shadow and turbulence creator.

    Please do come back with any test results!!

  • Others (Pierre Lesage and Jim Powers for example) know far more that I do about kites in high winds and from boats. I'd go with their advice.
  • My two cents:

    - Operating a kite from a boat in heavy weather while trying to view down links for images would be possible but difficult. Would need a team approach - kite flyer + imaging / sensor operator. The "weather" I am thinking about is storm force or gale winds...which always seem to correlate with sea rescues.... As for kite recommendations, the PFK Nighthawk is my recommendations. I have flown both the super kite and the Nighthawk. The Super kite with the flex wing design is too small to lift any load (i.e., multiple image sensors - even in a stiff wind. The Night Hawk can take a fair bit of wind!

    - My recommendation....

    - Consider one or more tethered drones...supplying both electrical power (to the drone and image sensors) and data communications....could stay aloft for hours or even days.....

    - Outfitted with multiple multi spectrum wavelength image sensors (including thermal)....on a gimbal stabilized platform with zoom capability.

    - Need to protect both the drones and the image electronics from weather conditions (and lightning strikes!).

    - Build in autonomous search patterns....down the road add in AI to sift the image data feeds in real time. The AI control could free the crew to drive the boat (or fly the aircraft) and focus on the rescue....a big need for drone pilot or camera operator....just clear message ....navigate to designated GPS location and due rescue.

    Yes...bit costly....but down the road...I see this coming...soon...


  • edited May 2017
    I mean no offense by offering this resource, but hope some might find it useful ( I read few of the articles,
    but find the headlines fascinating ).

    Center for the Study of the Drone

    They offer a weekly summary of "things drone ".

    Per this discussion, see: " The U.S. Navy is studying the possibility of using drones to keep track of sailors during man-overboard situations. (Naval Technology) " .

    The center is somehow associated with Bard College in New York ( also with a campus here in the Berkshires in
    Great Barrington, Massachusetts). I've had a few back-and-forth e-mails with the main guy. He had apparently
    done an article about KAP that I should track down...

    I had hoped to offer links here .... but, no dice. If you're inclined, take a peek :


  • SAR option...kite with KAP...not so much...


    Avy rescue drone
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