Close your DS and open it
you draw the sacred crest on the door in a single stroke. if you dont know what the sacred crest is, then your lost. the sacred crest is the triforces.
If you meant on Phantom Hourglass, you close your DS. I knew how to do that when I was 7.
all you do is close your ds and open it again
The sacred crest is the triforce symbol.
In the temple of the ocean king.
the triforce
The sacred crest is the image of three triangles put together to create one white triangle in the middle.
In the last boss, the crest is an hourglass. But, if you mean the other crest, it's the Triforce.
Close then open your DS system. That will transfer the crest onto your sea chart. Ciela will congratulate you. Take the blue light out of the Temple, then go get the salvage arm in order to retrieve the item hidden under the crest.
Close your DS Then open it again DON'T TURN IT OFF
Go to the area on the map where you transferred the crest.
the second crest is the tiforce if your asking about phantom hourglass