you have to talk to zauz the black smith first.
southeast
in sea chart 3
that's the last sea chart that you get in the temple of the ocean king.
You have to go to the ocean temple and get the next sea chart.
goron island in the southeastern sea chart.
it is in the 3rd sea chart which you get in B10 of temple of ocean king
does zauz have the information about the 4th sea chart on the legend of Zelda phantom hourglass
In the temple of the ocean king like all the other ones.
I think u have 2 have a hammer
if you meaqn by sea chart then all of them are in the ocean temple you can not obtain them all at once.
the same way you usually do! go through the temple, if your stuck talk to the skeletons.......
The 4rth sea chart