The equipment you need to take with you on a geocaching expedition varies widely depending on where you are geocaching and what the terrain is like. While the easier caches don't require anything more exciting than a GPS, going unprepared to a more difficult site is a recipe for trouble.
This discussion will assume that you will be going through the woods, either on a trail, off trail, or most likely, a bit of both.
Although there are people who seek out caches relying on their skill with only a map and a compass, this is decidedly a bad thing to do. Even those with the most skill can become lost, injured, or worse and require a quick escape. While it's not necessary to actually use a GPS on the hunt, it's importance as a backup device cannot be overstated. By making you car a waypoint, you are always assured of knowing where you are.
It's surprising how quickly a person can start to dehydrate. This can be avoided by taking along some water. Hint: if your water is half gone and you haven't found the cache yet, it's probably a good idea to turn back and return another day better prepared.
Someone who knows where you are
Don't go into the woods without telling someone where you are. It's just dumb.
Things happen. Accidents and weirdos can turn a nice afternoon into a nightmare. Take a friend along.
Your bare legs are vulnerable to all sorts of nasties such as snakes, poison ivy, poison oak, and sharp branches. Your exposure to these is dramatically decreased simply by wearing pants.
Sandals won't cut it. Shoes and socks are the way to go.
Watch where you are going. There are a lot of abandonded mines and wells out there. Falling into one would be a drag, to say the least. Plantlife can be a bummer. Poison oak and ivy can flourish in the wild and may be waist high. Also be especially watchful for wildlife. Snakes, spiders, bees, wasps, bears, cougars, and so on, can incapacitate you quickly.
This doesn't have to be something you take with you, but can be something you pick up off the ground once you've reached the cache. The thing about the locations that people hide their caches is that they are cozy. Snakes like cozy. Sticking your hand into a cozy snake hole is a good way to find a snake stuck to your arm or hand. You're not the crocodile hunter; probe around with a stick before you put your hand anywhere that you can't fully see.
Dogs and the woods don't mix. Even a well-trained dog can take off after a scent or a rabbit, or stick his nose where it doesn't belong and get a face full of skunk. Leave the pets at home.
A printout of the cache you are seeking
A simple printout can save you a lot of grief. Could be you need hint as to where the cache is. With the printout, you can decode the encrypted clue. You can also verify the caches coordinates, just in case you entered them wrong. Finally, and most importantly, a printout is evidence of your activities. Many geocachers have been stopped by police, park rangers, or other curious people because of their admittedly suspicious activities. By having documentation with you, you are almost assured of putting their minds to ease.
The sort of map handed out by the park should be sufficient. Lets you know where the marked trails are, rivers and creeks, and bathrooms and potable water.
A printout alone probably won't be enough to calm down those who are concerned about your activities. Always take along your ID.
Nice, But Not Vital Equipment
You can only trust the battery gauge in your GPS so far. You never know when it will show you to be at full capacity, only to have your batteries go completely dead in half an hour. This is particularily true if you use rechargable batteries.
Cell phones work practically anywhere nowadays. Bring one along. It will be a real life-line if you get into a jam. It's probably a good idea to make sure it is fully charged and to keep it off while in the woods just in case you really need it.
What do you do if you drop your GPS and it smashes into several bits, it falls into a lake or river, or it simply stops locking onto enough satellites due to cloud cover or bad weather? You know how to use a compass, right? Should you find yourself GPSless, you can follow your compass back to safety.
Better safe than sorry. By bringing a backup GPS, you'll be sure of finding your way back in case something happens to your primary. Be sure to either have it on the entire time, or at minimum mark your car as a waypoint.
First aid kit
You never no what sort of mischief might befall you. By taking along a small but well stocked first aid kit, you can treat those scratches and cuts on the spot instead of allowing the to accumulate dirt and debris as you trek back. A simple asprin can also do wonders to reduce the pain of a twisted ankle.
It's probably happened to you before in a non-active setting: you're driving home from work and you feel sick and weak because you are hungry. Imagine getting this feeling five miles into the woods. By taking along some cereal bars this can be prevented.
By providing excellent ankle support, proper hiking boots can go a long way in making your trip a safe one, particularily when the terrain is rocky.
A walking stick
Excellent for bushwhacking, or beating off a weirdo or wild animal, a walking stick is a good investment. You can get metal ones that collapes into a fairly compact package.
A radio or a bell
Animals are by their nature afraid of everything. And are most likely to attack when startled. By bringing along something that makes noise, you'll give them time to retreat.
While especially important at dusk or night, you never know when you'll need a flashlight: a dark cache hole, or maybe night time just caught up with you a bit faster than you thought it would.
Great for alerting others of your whereabouts and scaring away weirdos. Cheap and small.
Mace or pepper spray
To be used on the agressive weirdos.
You and your pals may be tempted to split up in order to find the cache as fast as possible. With a two-way radio, you can keep tabs on each other.
Why is it that whenever you see something cool, you left your camera at home? Don't let this happen to you!
Toilet paper and plastic bags
Toilet paper can come in handy if mother nature calls while on the hunt. The plastic bags are for carrying out your waste. Although it doesn't sound pleasant to carry this stuff around with you, it can have all sorts of negative effects when left in the wilderness.
One of those multi-tool Leathermans can be used for all sorts of unforseeable circumstances.
Many parks accumulate trash from visitors very quickly. Unfortunately, some of these visitors aren't all that careful when they dispose of their trash and may litter paths with it. Why not bring along a trash bag and make an effort to clean up some of the mess?
Sometimes you will have to move aside prickly vines or branches. With gloves, your hands will thank you. They are also beneficial should you decide to pick up other people's litter on the way out.
Change of clothes
So, you were attempting to balance-beam across that log in order to cross the creek and fell in, getting totally soaked in the process. A change of clothing would be great if you know you will have to do this sort of thing.
Although there are numerous debates as to whether or not insect repellant is hazzardous to your health, there are times when the mosquito, chigger, and tick population warrants its use. If you want to play it safe, get a brand that doesn't contain DEET.
Matches or Lighter
It's doubtful you will need to start a fire, but you never know.
Prevent a nasty sunburn and bring along some sunscreen.
You never know when it will rain, but you'll be a lot dryer if it does and you had the foresight to bring along one of those clear disposable raincoats.
What's that in the distance? A bear? A weirdo? Take a closer look through your binoculars to be certain.
Spare car key
Should you lock your keys in the car, or loose them while on the hunt, a spare can save you a lot of grief.
Rope can make climbing a steep hill considerably easier. Of course, someone has to make the trip without the benefit of the rope first.
Spare Log Book and Pens/Pencil/Sharpener
Log books get full and need to be replaced (don't take the original!). Also, pens dry up and pencils break. By bring along some extras, just in case, you can make the experience better for the next person.
Caches tend to go from interesting to not-so-intersting rather quickly. All the cool stuff gets removed and typically replaced with toys. While great for the kids, they are kind of boring for the adults. Some cool things you might consider:
The possibilities are really endless. It's always a good idea to bring along some smaller stuff, even if you intend to leave something larger. Oftentimes caches are too small or full to hold a larger item.
- coins, new or old
- pins (from your home state, etc)
- badges suitable for sewing on a backpack or jacket
- pocket knife
- cookie recipe
- marbles (technically a toy, but marbles are cool)
- Yo-yo (another cool toy)