How to Open a Coconut

From WildernessWiki.org

Coconuts can be an excellent source of both food and water - if you know how to open them! It's actually much easier to do than most people think. Here's how:

Opening

Before anything else, use your knife or other sturdy, pointy object to puncture the coconut's husk. This will allow coconut water to drip out. Either collect the coconut water (not the same thing as coconut milk) in a container, or drink it straight from the coconut. In a survival situation, this is an excellent source of water.

The second step is very straight forward - crack it open by hitting it with something hard. A rock or sturdy log will get the job done, but a more elegant solution is to use the back of a heavy knife. Hold the coconut in your non-dominant hand, and hold the knife with the other. Crack the knife down against the coconut, and a long crack will form around the circumference of the coconut. With one to four blows, the coconut will open, and you can enjoy the meat inside.

The type of coconut that we're talking about is actually just the seed of the much larger coconut fruit. In the wild, the chances are that you'll have to deal with the full fruit. To open this, you can just smash it against a boulder, or if you have a large knife, use it to slice away at the outside.