With Epona, you can reach some new areas by leaping over fences. Goto the beachy area on the
northwest corner of the main map. Jump over the fences in your way to get to Great Bay. It
is good to have a map of this area, so if you don't, you might get lost easily. One of the
little baloon guys will sell you one, maybe the one on Milk Road. Anyways, walk along the
beach until the change to take a hint from your fairy comes (UpC button). She will point
out a Zora Person in the water with seagulls floating overhead.
Swim out to this Zora, and try to talk to him. When that doesn't work, get behind him and
push him over to land. When he comes to, he will play you a song and shout out a few words
before collapsing. Play the Song of Healing, and you will go through a short cut scene
that will end in Link getting the Zora mask.
Now that you have the Zora mask, you can get a heart container by defeating the monster at
the bottom of the waterfall on the next map over. Becareful, it is hard to fight underwater,
and this monster can suck you up and sometimes steal things.
On this same map, there is also an empty house with a cracked wall. Bomb that wall and you
will find the 2nd set of 30 golden spiders to defeat. I will come back to that later, in
Chapter 15.
There is also another heart piece back on Death Moutain if it is thawed. In the room with
the rope bridges and Goron races, there is a chest on the ground underwater that Zora Link
can open.
You can skip the next chapter and save it for later, or do it now. The order you do some of
the next events in is not very important.