This intrigued me, I've done exercises like this in that past and I thought it would be something that a lot of guys here would have fun with.

List your four items in your answer, then provide your rationale for each item.

enter image description here

  • Are we given the latitude and longitude of the island?
    – ab2
    Commented Jan 24, 2016 at 12:27
  • 1
    No, but most of the islands in the ocean are in the South Pacific, so for the sake of this question we can assume the island is some where out there.
    – ShemSeger
    Commented Jan 25, 2016 at 0:47
  • 1
    I think I'll take the rifle, and then tell whoever's witholding 24 survival resources from me to hand them all over! (I kid, I kid!)
    – nhinkle
    Commented Jan 28, 2016 at 22:16
  • 3
    I'm not clear why this is in Meta? Meta is for questions about the working of the site?
    – user2766
    Commented Feb 2, 2016 at 10:00
  • 1
    @Liam I guess it could be considered to be primarily opinion based. I don't think ShemSeger is looking for one definitive answer to accept, but what different answers people come up with. On many other SE sites this wouldn't be possible neither on the main nor the meta site (people would down- or closevote). Kudos to this community that such interesting questions can live here despite not being strictly Q&A but more of a discussion. +1 Commented Feb 2, 2016 at 20:02
  • I mean I don't want to be a kill joy. this one question isn't doing any harm and is entertaining. I just don't think a raft of these on Meta will be in the spirit of what meta is for.
    – user2766
    Commented Feb 3, 2016 at 8:22
  • 1
    what am I wearing!?
    – cr0
    Commented Apr 18, 2016 at 14:54

6 Answers 6


Let's see:

Tarp. Can be used for shelter, water collection, easily seen as is clearly not natural, and if you boil salt water you can use it to collect the water vapour.

Knife. I simply can't list everything this is useful for. If I could only take one thing it would be a knife.

Mirror. While you can make a crude mirror it would never be as good as a real one. Signalling, lighting fire (potentially, it is technically possible to light a fire with any mirror, but being flat it would be very difficult), making sure any cracks or holes don't have something that is going to kill you in them.

First Aid Kit. I am very wayward, I will hurt myself at some point. That and first aid kits in the UK generally have water purifying tablets in them, mosquito repellent, etc.

This is where it switches up a bit, the variables in the listed equipment.

First Aid Kit. Some first aid kits I have had in the past have included a mirror. Others have included highly reflective thermal blankets which, with a bit of time, could be converted into a mirror. If either of these were the case then the mirror would not be needed.

Knife. Depending on the type of knife and blade length / width, it is perfectly feasible to use a knife as a mirror. Once again removing the need for the mirror option.

Taking these factors into account, I would switch the mirror for a Flare Gun. It is a main signalling device for someone in distress. A mirror could be missed by someone not paying attention to your direction. If they miss a flare well ... might be safer on the island.

As a side note. Shop brought first aid kit or my first aid kit? If it were the one I take everywhere with me all I would need extra is some tarp and the flare gun.


I assume the island is in the South Pacific (tropical or subtropical). I also assumed that it was off the shipping lanes and that I would be there for the long haul -- this was different from ShemSeger's assumption that there would be an intensive search and he'd most likely be out of there in 48 hours.

First, I make sure of shelter, so #1 will be tent or tarp

I need to continue with shelter, specifically shelter from the sun by clothing; #2 will be either a knife or saw to cut fronds for a hat and a cape or shawl like thing for the body.** My main exposure will be early morning and late afternoon so I'll pass on the sunscreen, which will run out anyway.

For #3, I'll take the mirror, unless it is planar. The mirror can signal and focus light for starting fires. The matches will be quickly used up, so I won't take them.

What I don't have are items to catch or cook food, to purify water or to go to another island. But the knife can make cooking implements, ropes and even a raft from the coconuts palms. A South Pacific island will have rain on the windward side, and water collectors can be made from fronds..The tarp can also collect water. #4 is the first aid kit, provided it is amply supplied with anti-biotics, fungicides and pain meds. I figure I will be clumsy at first.


#1 First Aid Kit. Desert islands suck, but the circumstances that put you there probably didn't leave you in the best condition. You'll probably go for this before you even think about "I only have time to grab 4 items".

#2 Knife. This gives you the ability to make many other things which you'll need, either from other supplies or found materials.

#3 Raft. Not for rafting. Sun exposure is the biggest danger in this environment, but also think about the monsoon season that could be coming (or you're already in). Shelter is big, and has a large psychological boon as well. Many would say tarp, but the raft is almost a prebuilt shelter. And if you just need the material, a raft typically has a bigger surface area than a tarp so you're getting more material. That material is also designed to be highly noticeable. And by the picture, the raft is coming with some bags :)

#4 Fishing rod. Yes, you can make cordage and hooks. Again, I go to the psychological aspect. You feel like you can survive when you have an ocean full of fish and a fishing rod. This may keep you trying longer when time is your best resource.

Honorable mentions. Fire is important, both for heat and for smoke. A flare gun would help you get rescued and give you fire, but is very limited in how many times you use it. A mirror would be a better rescue tool, but a flat mirror can't realistically help that much with fire. Matches would also help with fire, but would be limited. Rafts are made to be noticeable, so it's going to pull triple duty here. As for fire, you're gonna have to use that knife and go old school. Depending on the first aid kit, you might have some help there as well.

  • I think the fishing rod would get fouled up too quickly and maintaining it would be too hard. In the end I think you'd spend more time fussing with it, and eventually have to abandon it. After that happens the psychological benefit from the fishing rod may become negative if you started thinking you "wasted" one of your picks on it instead of grabbing XYZ.
    – Erik
    Commented Feb 4, 2016 at 18:32
  • Possibly, but get one fish and you have fish bones which are great for making more hooks and other tools. Fish scales also can be used to create a reflection device. It might not last forever, but it helps you get other resources and is more renewable than most other things on the list. @Erik you do have a good point though :)
    – David R.
    Commented Feb 4, 2016 at 21:54
  • Very true, it doesn't need to last forever if it gets you things you couldn't get otherwise before it dies. I tell you what, I'd rescue you just to see your fish scale signal mirror. :) Your MacGyver skills are way better than mine if you can pull that off!
    – Erik
    Commented Feb 4, 2016 at 21:58

I've done several exercises in the past where we were required to rank items by importance and usefulness, and then compared our answers to the rankings provided by experts in the military. When in a rescue situation, which I can only assume someone stranded on a deserted island would be in, your number one priority–after addressing any critical injuries which may have resulted from whatever circumstances put you on the island–is going to be getting rescued, and in any rescue scenario, the first 48hrs are the most critical.

There is a chance that someone, or yourself may have sustained injury, if so, then I would be tempted to choose the first aid kit, but bandages can be made using torn shreds of clothing, and other materials which may be at your disposal on the island. The only type of injury that people need to be concerned about in the first 48hrs is a deadly bleed, everything else is either survivable, or beyond anything you could remedy with a standard kit. Deadly bleeds can be stopped in most cases simply by applying pressure. Infection is less of a concern in this situation, because like I said, we're planning on being rescued in 48 hours, and the available salt water in the ocean is an effective bacteriostat and can be used to clean any wounds.

That being said, my choices are:

  1. Knife
    The most indispensable survival tool is your trusty blade, which has innumerable uses in any survival situation, it can provide you with food, shelter, and fire, as well as provide you with a means of defense (if necessary). It is also useful for cutting bandages, building splints and cord, as well as creating more tools.

  2. Mirror
    Out of all the items on the list there are five which I would consider valuable for attracting the attention of ships or aircrafts:

    • Flare Gun
      For obvious reasons, it's the only item on the list designed exclusively for advertising your location and attracting much need help. It is visible both day and night, and it can also be used to help you start a signal fire, or even as a defensive weapon.
    • Flashlight
      It can be used to communicate through morse code (some flash lights even have S.O.S. in morse programmed into them) but the disadvantages somewhat outweigh the advantages. For one, it can only really useful for signaling at night, which is not likely going to be when the search parties are going to be out in full force. It provides light, but so does fire, and you can always make more fire, your batteries will eventually run out, and then you're left with a useless tool in rescue doesn't make it to you in your 48hr window.
    • Matches
      Matches = fire, which is probably your best chance of attracting attention from the greatest distance. A column of smoke can be seen from over the horizon, and is much more constant than a single flare. Fire also cooks food, but you aren't going to starve to death in 2 days. Number of matches is limited, you will eventually run out, there are other ways to start a fire.
    • Tarp
      A large blue square on a white sandy beach is very visible, from the air especially, and will attract attention, especially from people who are out searching for you, they will take the time to investigate. We was once beached because of a sudden storm, and propped our big green canoe up on our paddles to signal our location–search and rescue told us we were really easy to find because of how far away they could see the canoe. The tarp could also be used for shelter and gathering water.
    • Mirror
      Especially a mirror as large as the one shown can catch a lot of light, and be seen from massive distances, great for signalling planes and ships which are visible on the horizon, can also be used for morse code. Not effective for signalling at night, but mirrors can be used to concentrate light and start fires, by lighting a small fire during the day, you can have light to see by at night, as well as flame to start a bigger signal fire if you needed too. Good signal, plus source of fire plus unlimited use makes the mirror my choice, with Signal flare as a close second.
  3. Flare Gun
    A very close second to the mirror. Remember, rescue in the first 48hrs is crucial, so you need all the attention getting power you can manage, even with a mirror in your possession, the flare gun is still probably more valuable than everything else on the list in those first couple days.

  4. Tarp
    Highly visible, so it's another aid for your would be rescuers, but it also has a number of other uses. One thing lacking from the list is a practical receptacle for gathering water, and you're going to die from thirst before you die from starvation, if you haven't died from your wounds yet. You could likely make a receptacle from what you have available on the island, especially if there is any bamboo growing there. The pot can hold water, but it's not really practical for much else unless you want to also make a fish stew, and what if there aren't any sources of fresh water on the island? You could use the pot to distill sea water, but you'd still need something like a tarp to catch the steam and condense it again. The water filter can't desalinize sea water, so it's pretty much useless. A tarp could catch rain water, and keep it in make-shift tub dug in the sand, or it could be used to make a solar still (as horribly complicated and time consuming it would be...).

Some people may ask why not just use the inflatable raft? To which I would respond with this:

enter image description here

Although I suppose the raft could be a very viable substitute for the tarp, it would perform all the same functions as a tarp, still be super visible if it was a bright colour, and would probably prove superior for distilling sea water... closed container and valves and all... Ok, so I might choose the raft over the tarp, but not for use as a boat.

So there's my list, I'd be interested in any comments or criticisms anyone might have, and I look forward to seeing more lists posted.

  • I came to the same conclusions about the raft. It's equally good as the tarp for some things, and even better than the tarp at others. Not having grommets would be the one downside.
    – David R.
    Commented Jan 28, 2016 at 14:45
  • 2
    @DavidR. Every rubber raft I've ever owned has had a perimeter rope, which works just as well if not better than grommets would.
    – ShemSeger
    Commented Jan 28, 2016 at 15:32
  • Great comic by the way
    – Erik
    Commented Jan 29, 2016 at 20:55

Do we know if we have a source of fresh water on the island?

If we don't know we have fresh water I'd choose:

  1. Knife
  2. Mirror
  3. Pot
  4. Raft

The knife and mirror are pretty self-explanatory. The interesting choices are the raft and the pot. Since we don't know if we have water we need to solve that problem first. The raft can be hacked up and used in conjunction with the pot to create a solar still. The raft can also be hacked up to provide shelter from the sun.

If we know we have fresh water I'd choose:

  1. Knife
  2. Mirror
  3. Water Purifier (uncertain water quality) / vitamins (known good water supply)
  4. First Aid Kit

Once again the knife and mirror are obvious. The water purifier is to protect against bad/brackish water. The first aid kit is dual purpose. Firstly it will help me prevent death by infection. Next it has lots of little bottles and tools that would be helpful when re-purposed. The vitamins are to combat dietary deficiencies since I'm probably going to be on the island for a long time.


Top choice, in order of importance.

  • Knife - The single most usefully tool for modifying your environment.
  • Hiking Boots - If your going to make the best use of available resources you have to move around. Islands tend to be volcanic or coral, I am going to want to protect my feet.
  • Compass - When your alone, the only one who is going to rescue you, is you. Pick a direction (east or west) and keep going you will hit land at some point. Even odds on worst case scenario you are 9,900 km (6,150 miles) from shore.
  • Tarp - I can paddle about 2 miles an hour, if I paddle 16 hours a day it is going to take about 192 days to reach shore. A sail would make things go much quicker.

The Pacific reaches its greatest east-west width at about 5°N latitude, where it stretches approximately 19,800 km (12,300 mi) Source

  • You're more brave than I am to sail away from an island on an improvised sailboat Captain Bligh. :) As far as navigation goes you can trade in the compass for a cross staff for sightings at night and use a sun compass during the day. Both of those would be better tools to correct for drift, which a compass alone can't do.
    – Erik
    Commented Feb 16, 2016 at 20:49
  • @Erik Only a compass was in the available choices and I know how to use it. There are worse things then dying on the open sea, spending decades alone on an island waiting to die of old age is one of them. Commented Feb 16, 2016 at 22:07
  • I know they weren't on the list. I was trying to say you can easily improvise effective navigational aids to sail a latitude. That would free you up to take another item that might be useful and hard to improvise. Rope to rig your sail might be one of those items for example.
    – Erik
    Commented Feb 17, 2016 at 18:33
  • 2
    New Question What Navigation Aids can I make on an island with only a knife? Commented Feb 17, 2016 at 19:00

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .