One of the things you come across when you understand how to geocache, are geocoins.
Gecoins are trackables that are used in geocaching. They are large custom made coins, usually moulded rather than pressed, with a coloured artwork applied and baked.
Geocoins are often beautiful works of art and many that get (*cough* stolen) lost. I can't understand the mindset of someone who will deliberately take one of these coins and then not log it. Some of them are worth a bit of money.
Here are some places where you can obtain geocoins:
A Travel Bug (TB) is one of those aluminium tags attached to something that you find in a cache. They are items that you can remove from a cache without needing to swap with anything else. When some people are learning how to geocache they aren't always sure of what is the right etiquette when it comes to handling TBs.
The idea of TBs is that geocachers move them to another cache so that the TBs have little adventures of their own. TBs can log tens of thousands of miles as they travel around the world.
Every time someone retrieves or places a TB its owner receives an email and can track its progress. In this way they can enjoy its travels vicariously. The geocaching site has a feature where TB voyages are plotted on Google Earth. It's amazing to see how far and wide these things travel - just by hitch-hiking!
So what do you do if you find one? What is the correct etiquette?
Firstly realize that they belong to someone else and while it's in your possession it's your responsibility to look after it.
You should place it in another cache as soon as possible. Don't leave it for many weeks before you place it somewhere else. The only exception I would make to this is if you are planning to go on an overseas trip and the goal of the TB is to travel around the world.
The cache in which you place it should be one that is visited fairly frequently. In other words don't hide it in a cache that is rarely visited, such as a difficult puzzle cache, or one in a remote location etc.
If you come across a TB in a cache that is visited infrequently, do the person a favour and move it on. They'll be very grateful.
If you own a TB, please don't attach some large object to it. It can be very difficult to find a cache large enough to accommodate something large. If I find such a TB, I usually won't move it on for that reason.
If you do lose a TB that is in your possession, inform the TB owner. I'd rather know than have to chase you up. One of my TBs didn't move for months. I kept following up with the last person who eventually placed it somewhere. It took 6 months though.
A GPS unit is the primary tool for geocachers so it's important to have a really good understanding of how the system works, the limitations and things to consider when using them. A good working knowledge of the system will help you to understand how to geocache properly.
The GPS system is one of the great inventions of the 20th century. It has revolutionized navigation and many applications have been developed that make use of this system.
The system that we use for geocaching is called GNSS, or Global Navigation Satellite System. It was set up and is operated by the US Air Force and costs billions of dollars. We get to use it for free!
Basically GNSS is based on about 24 satellites that orbit the earth and transmit a radio signal towards the ground. The signals from the satellites are all synchronized to incredible accuracy by a ground-based atomic clock.
The GPS unit that you hold in your hand is basically a radio receiver (not a transmitter!) that is able to calculate the time differences from the signals that it receives from the various satellites that it can "see" in the sky above where you are standing.
Remember that these signals are travelling at the speed of light, so the time differences from the various satellites are minuscule. Even so, your GPS can detect these differences and triangulate where you are down to about 3 metres at best. The optimal place to get the most accurate fix is when you can see clear sky all around, such as on the top of a hill, or out on the water. The signal is degraded if you are, for example, under trees, in a canyon, in amongst tall buildings or anywhere you don't have a clear view of the sky.
The GPS receiver is a marvel of modern technology. To give you an idea of its sensitivity, it is equivalent to trying to see a 100 watt light bulb located 10,988 nautical miles out in space!
So what does this mean for you?
It means that next time you're trying to find a geocache be aware of the limitations in the accuracy of position. The best accuracy your unit can achieve in the most optimal conditions is about 3 metres (~10ft). So your search radius is about 3 metres from where your GPS says is GZ - and that's assuming that the cache owner has published accurate co-ordinates. If you are under trees, in a canyon or some other difficult location, your search radius may be wider.
It also means that when you are placing a cache don't just hide the container, mark the location and leave. That's a recipe for inaccurate co-ordinates. Spend the the time to average the position (a good GPS has this function) to get accurate co-ordinates - especially if it's in a location where the signal is not so good. Your fellow geocachers will have loving thoughts towards you if your co-ords are accurate.
This is a really important subject when you learning how to geocache, so we'll go into more detail elsewhere.