4.2. Containers Explained
micro: Less than 100ml. Examples: a 35 mm film canister or smaller, typically containing only a logbook or a logsheet. A nano cache is a common sub-type of a micro cache that is less than 10ml and can only hold a small logsheet.
small: 100ml or larger, but less than 1L. Example: A sandwich-sized plastic container or similar. Holds only a small logbook and small items.
regular: 1L or larger, but less than 20L. Examples: a plastic container or ammo can about the size of a shoebox.
large: 20L or larger. Example: A large bucket.e.g. 5-gallon bucket (about 20 liters)
other: See the cache description for information. Unusual geocache containers that just don't fit into other categories.
Generally, you want to use a container that is:
- Waterproof and won't degrade in the sunlight
- Containers should be waterproof to protect from rain, snow, ice, condensation,e, etc. A compressed seal is often the best method to protect your geocache from being a wet mess inside.
- If your location in direct sunlight, choose a container that will not degrade quickly from sun exposure
- Suitable for your particular environment
- Can this forest support a nice, large geocache with room for many trade items?
- Should I use a micro in this highly-populated, urban environment?
- Not going to look like a threat to anybody
- Will this object hidden in this manner likely be reported to the police as a bomb?
- Containers that are transparent and clearly labelled as a "geocache" are best
Below are some general examples of what people use for containers. Some are better than others.
An excellent geocache container are transparent water-tight containers with clasps which fold over part of the sides, to clip the lid to the base. Shop Geocaching carries a branded line of these products. Lids are usually made from the same material as the base, which reduces the loss of quality of the seal over time. And of course the clasps make a excellent seal.
Military surplus ammo boxes make excellent geocache containers, provided that they have a rubber gasket to ensure a good seal. This sort of geocache can sometimes even survive the area being flooded.
This picture shows the two most common sizes of ammo box. They are sometimes referred to as .30cal and .50cal, respectively. They are usually sold in the color shown, which is generally a good base for any camouflage which you might add.
It's a good idea to erase any original military inventory description such as you can see on the picture. You don't want a person who accidentally finds your geocache to think that it might contain live ammunition. Better still, once you've eliminated the frightening words, you could paint "Official Geocache - Contents Harmless" in large, friendly letters on it. Although this shouldn't, in theory, mean very much (a terrorist could easily write "Contains Kittens" on a bomb, after all), in practice it can mean the difference between your local "muggle" opening the box and discovering our game, or calling the Bomb Squad.
Many original military markings can be removed by isopropyl alcohol (rubbing alcohol), with sand paper or with a wire brush. You can also paint over it.
This picture shows an older type of ammo box. It doesn't have a rubber gasket, which means that moisture can get in eventually. This will make the logbook and other geocache contents damp; it will also start to produce rust, which will permanently stain any contents which are not in sealed bags. If you have a container like this, try to reserve it for a dry place.
All of the above ammo boxes would normally be considered "Regular" size containers. The .50cal box sometimes appears as "Large".
Boat Supply Containers
There is probably a better name for these containers, but they are sometimes advertised as storage bins to keep supplies dry on kayaks or small boats. They come in a variety of heights, but generally they are all about 25cm/10 inches in diameter. They are often durable and watertight with a gasket in the lid. They make some of the best large containers you can find. Their disadvantages are cost (unless you can get them used), possible degradation in sunlight and they tend to be white with either red or blue lids - which makes them highly visible. Because they are made of polyethylene, they are hard to paint any other color.
GladWare and similar products: Generally a Poor Geocache Container
The name "GladWare" corresponds to a range of products, but to geocachers it refers to the thin plastic food storage containers which look like this.
These are fine products for storing food in your refrigerator, but they are not designed for any form of exposure to outdoor conditions. They will quickly become cracked and the lid will not fit properly after being out in the weather for just a few days.
Experienced geocachers avoid using this kind of item as a geocache container.
Food Containers and Other Packaging: Generally a Poor Geocache Container
It can be tempting to use an ice cream container, coffee can, cookie tin, or some other apparently waterproof packaging to hold a geocache. It's free, and you might even feel that you're helping to recycle. But like GladWare, these containers are designed to be used once only. They are just strong enough to get their contents to you and keep it fresh long enough for you to consume it. All of the disadvantages of GladWare apply to the plastic in these containers, and outdoors the tins soon rust and fill with water. It's hard to completely remove the odor of food from these containers, which may attract animals.
To some people, Tupperware is almost a synonym for geocache. Whether it's original Tupperware, or a similar box from Rubbermaid, Curver, etc, everyone recognizes a polyethylene box with the push-to-seal lid as being a good choice. We'll call these containers "P-ware" from now on P for polyethylene to avoid having any one firm's lawyers get upset at us when we point out their main disadvantages for geocaching, which are:
- Shape. P-ware boxes are often long and wide, but not deep. By the time you've got a logbook and a few trade items in there, adding even a modest Travel Bug can make it hard to get the lid on.
- Cost. These boxes are not especially cheap. (The same can be said for ammo boxes, but sometimes you can pick those up for almost nothing, and they almost never need replacing.)
- Limited weather resistance. Over time, due to different rates of expansion of the different materials which are often used for the lid and the base, the lids will lose their ability to seal properly. If the box is hidden under stones, at some point the combination of the weight and repeated temperature changes will cause cracking.
- Degradation in sunlight.
This is not to say that P-ware boxes do not make good geocache containers, but they do require more maintenance visits than, say, ammo boxes.
The classic "Micro" size geocache is a 35mm or APS film canister. However, not all of these are created equal.
The most commonly seen film canister has a black body with a gray lid. The gray lid appears to form a seal inside the black main part, with the outside of the lid forming a lip which looks like it might keep water off. However, it does not. In the tough outdoor world, you will often find this kind of container with a soggy log sheet.
The other kind of film canister is usually opaque white and has a much better reputation for keeping the log dry. The lid fits snugly, almost forming a proper seal; certainly it keeps more moisture out than the first type of film canister.
A plastic pill bottle has some good qualities for a micro geocache (albeit a large one): the plastic tends to be very tough and the lid usually fits well. However, water gets in quite easily.
Often, micro caches are disguised as other day-to-day objects, such as bolts, reflectors, rocks, and even chewing gum! These can be especially tricky to find, but after a while checking the bolts under benches for wiggle will become second nature. It can often be difficult to retrieve logbooks from these containers, so remember to bring tweezers or a similar tool to help you out.
Bison tubes are a type of micro cache that are often attached to a key ring, making them useful for hanging in trees or under benches. They come in a few different sizes and tend to be pretty waterproof. They don't hold a lot of logbook paper, and the logs themselves can sometimes get stuck inside the capsules.
This is a special magnetic metal container, possibly the smallest of containers. It is usually pretty waterproof. Logs can get jammed inside occasionally; if this happens folks use a tool (like tweezers) to get the paper out.
There are many other possible containers: bison tubes, waterproof matchboxes, water bottles ... Some are better than others.
If you would like to purchase a container from Shop Geocaching, we do carry a nice selection. However, as you can see above, many options exist that do not require an additional purchase.
Many thanks to Volunteer Geocache Reviewer riviouveur and the geocacher named paleolith for helping to develop these descriptions.