Stuck very early. Think I missed something important.

[Epicenter]

I'm stuck in one of the first areas. The odd Naija-like creature showed me the 'vision' already and I went to the next area, I passed a red stone and saved my game.  I think this area is called Secret Cave Passage. I can go through one area but it is just a big dead end. If I go back I can't find any other routes to take. There's a bunch of violet coral and the skeleton of a .. whale? .. There's also some of those colored plants you can sing to, that when you match their color give you items. I see what looks like an exit but a big boulder blocks the way. I assume I need to do something, get some song, etc. to clear it but I can't seem to find it I think I missed some important tip the game gave me.

Also, what if anything is the function of the small and big jellyfish? by big, I mean the HUGE one with the little sphere in the middle of it. Sorry for how vague this post is. So here is a screenshot to help

http://img525.imageshack.us/img525/5529/secretcavepassagebv1.jpg

Thanks very much for any help!

[Don Andy]

oO This gotta be the most straightforward part in the whole game. This is a linear tunnel that you just have to swim along to the end, where you end up in the Home Waters, from there, it's pretty much free exploration (although I'd advise you to check out the bottom of the map first).

If you double-click on the Minimap or press Q a map comes up. That should help xD

[Quemaqua]

Yeah, just head to the end.  What might be confusing you is the exit?  You'll essentially travel through the "end" of the map, which will then take you to another portion of the world.  If you look on the minimap in the lower right, these exists are identified as big white circles-within-circles, almost like buttons or something.  There are red ones too, which represent the save crystals.  The white ones won't show up on your main map because the exits should be plainly obvious to you there, and the save crystals show up on your map as... well, little red save crystals.

[Epicenter]

Right, I understood how the exits work, etc.- But I already passed Home Waters. This is beyond that. Home Waters was before the 'vision' sequence I described...  we must be thinking of different places. Did you look at the image?

[Don Andy]

Yes, that is the small tunnel you start the game in :/

[Epicenter]

I got to Naija's home by going the other way than the game led me (counterintuitive.) but now there are over 15 exits on my map and I can't go to any of them, they are all blocked off. I could spend 2 hours trying every one only to find a barrier. Why do they even show up if I can't reach them? It's really frustrating.

[Zam]

Go to the bottom cave (Very bottom) and to the right (starting from Naija's home) You should go through a small u-bend and then be at an exit.

Explore in that, that gives you your next spell that basicly opens up the entire area.

[dhakkel]

I got to Naija's home by going the other way than the game led me (counterintuitive.) but now there are over 15 exits on my map and I can't go to any of them, they are all blocked off. I could spend 2 hours trying every one only to find a barrier. Why do they even show up if I can't reach them? It's really frustrating.

It's called exploring, dude. If you don't like doing it then you aren't going to enjoy this game, I'm afraid.
None of what you just said is correct, tho. The game doesn't lead you anywhere after Naija's home. The currents go towards her home. After that it's up to you to find where to go.

There also aren't 15 exits. Counting caves with stuff in them, there are about 8 or 9.