LAND-Shark Emergency Survival Bag – Experience? or Reviews?

[David Wills]

I would love to get hold of some of that reflectatherm for quilts when a VB is too clammy.

[Joshua Mitchell]

Okay, it’s about time for me to chime in…

Some points about radiant heat loss

1) Radiant Heat Loss / Gain does NOT happen through opaque material, period (well… there are probably some crazy materials but those are way exotic).
2) Radiant Heat Loss / Gain happens across distance separated by empty space (or air filled space)
3) The ‘delta T’ involved is the two surface temperatures that are separated by empty space.

AKA The ONLY place you can have radiant heat loss be significant is when you compare the outer surface of your sleeping bag to the inner surface of your shelter (everything else is touching or close enough to touching that convective / conductive more than dominates). If you have prepared your gear adequately, this delta t is essentially zero.

Quick and easy test… take your hand out of your sleeping bag, ‘feel’ the outside surface then ‘feel’ the inside surface of your shelter… I’d bet dollars to donut that, if you have an adequately rated sleeping bag, both are going to feel cold (aka zero delta T).

Note, this also explains why you can feel colder sleeping under the start than in a tent… in that case you’re comparing your sleeping bag to the coldness of outerspace… however you don’t need a ‘reflective barrier’ to block this you just need an opaque barrier.

[John S.]

I saw an older physiology textbook stating that lining garments with gold was good for reflecting heat. It mentioned that these garments enabled Arctic expeditions to carry less weight in clothing. Does anybody know anything about this?

[Joshua Mitchell]

“I saw an older physiology textbook stating that lining garments with gold was good for reflecting heat. It mentioned that these garments enabled Arctic expeditions to carry less weight in clothing. Does anybody know anything about this?”

It might add some benefit, however the added benefit from radiant heat transfer blockage is likely overstated. The reason it might add benefit is that, during movement the clothes are not likely to be right against the explorers skin it would reflect radiant heat back to the skin… however realize that this would only happen when the insulation is less sufficient.

However, I suspect that the actual benefit was that, in order to reflectivize the fabric they likely needed to make it a tighter weave resulted in more wind-blockage and it acted as a semi-VB.

[paul johnson]

Not the Antarctic, but…

a sister division of the company i work for makes the NASA astronaut’s space suits. An ultra-thin metallic layer is used in the suits to keep out radiant heat and reduce the cooling requirements of the suit.

[David Wills]

From what I have gathered, the use of reflective layers would only be useful in emergency situations when underinsulated (stand alone summer bag, or my 40* quilt in 30* nights :), my plans to begin with), or as a tarp to reflect significant heat gains from a fire to the body, or in the summer to reflect the sun away for coolness. Sounds like its pretty versatile nomatter what time of year it is though. It’ll be a fun test to see how low I can go with this reflective VB bag in my 40* quilt.

“If you have prepared your gear adequately”- now what’s the fun in that?

[Jennifer Looy]

Good Afternoon Backpacking community,

My name is Jennifer Looy, I am the daughter of the inventor of this product. I was reading though everyone’s reviews and comments in regards to the Land/Shark product. I appreciate everyone’s honesty and welcome any questions or feedback in regards to the product.

To answer your questions:

Has anyone USED THIS?
I have had personal experience with the product in instances of land (backpacking in Montana) and water use of this product (FAR 135.331 Crewmember Training Class, Pool Demonstration.) See below for additional comments.

Ever seen it in real life?
Yes, I aided in the manufacturing of this product.

How durable did it seem?
The bag is intended for one use ideally. As I am beginning to gather the general backpacking community would prefer a more durable product that could be used in multiple instances. Although the material is strong it would not be ideal for multiple uses. The inventor of this product initially wanted something for water emergency situations.

Was the material quiet?
Its is not loud like one of the crackly space blankets, but it not completely quite either. When getting into the bag you will be heard. Once settled into the bag it is relatively easy to keep quiet.

What situation did you use/intend for?
My experience with the bag on land is as follows: During my experience we ended up using the bag for a heli-vac of one of our team members who took a bad spill down a snowy mountainside. We thought she might have back or neck injuries. We had to keep her on as flat of a surface a possible so we took turns digging a ramp down to a place where the helicopter could land and sliding her slowly down on the land shark in this instance it was slick enough that it acted as a nice sled. After the bag had been used we ended up just messing around with it. We cut it up and made snow boots. Seeing as we tried our best to dry out our snow boots during the night. We used it to carry water, etc.

My experience with the bag in a water situation is as follows: We host a FAR 135.331 Crewmember Training Class for the Pilots and Flight Attendants of the Corporate Aviation Industry. Its is a class taught by Tim Kneeland (who has a long resume mostly involving SERE and various other survival techniques, obviously in the instance of Corporate Aviation he teaches people how to survive while trying to do things to be found.) At the end of the class day we do a demonstration with life vests, a life raft, land/shark, and various other ways of keeping afloat and alive in a ditching situation. I take the course every couple of years. After donning a life vest you open up your land/shark and get in it water and all and then you do your best to assume the fetal position or any other non moving position. The goal of both the land/shark and the exercise is to show people how much water takes heat away from your body. As soon as you get into the land/shark and stop moving you can feel a layer of water almost stick to your skin and begin to warm. You feel warm as long as you are doing your best not to move and there is no current over your skin.

I apologize for not being the most articulate person, but I hope that some of my words have answered your questions.

Warm Regards,

Jennifer Looy
Corporate Air Parts, Inc.
+818-997-0512
[email protected]
http://www.landshark-online.com
http://www.corpairparts.com

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