h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

So...back to my original subject...

Oceans give the appearance, after a short period of study, to change frequently, but in fact do not. Lakes give the appearence, after a short period of study, to remain stable, but in fact do not.
A lake is nice because it is easy to understand, and once you understand it, there's nothing more to know. If it happens to change while you're still looking at it, it's easy enough to get reaquainted with the new thing. You always know what to expect, but if it's a pretty lake, would you really mind?
Oceans are more difficult. There are three stages to mapping out an ocean. The first covers the surface. It's not very hard, and you can bet that just about everyone else has mpped it out already. The second covers mostly everything else. Since lakes are more common than oceans, many people try to map an ocean the same way. This doesn't get them very far, but most never know the difference. So very few people get to mapping this second part of the ocean. It may be completely different than it seemed from the surface. There's a real sense of reward when you finish mapping this out. Because of this, many people stop here, too, as if the ocean were a sea (something I've not discussed yet, as it's pretty obvious from the above what it is). But there's one level still to go.
The third stage in mapping an ocean is incredibly difficult, as there is nothing you can do on your own to acheive it. You are completely at the mercy of the currents, kicking up whatever they can whenever they can. Often you will find things that are beautiful, things that are disturbing, things that glitter, and things that drip with toxic sludge. The question then is wether to ignore the bad in light of the good, or ignore the good in light of the bad. In any event, once you've reached this stage in mapping, it could be dangerous to swim for too long.