scarfed boards - face or edge bevel?

[Rich D]

I'll be glueing up some boards soon using my tablesaw scarfing jig to cut the scarfs. 

Should the scarfs be on the face of the board or on the edge? Is one way stronger than the other? 

 

This will be 3/4" x 1 1/2" stock and 3/4" x 3/4" stock. It will be for kayak gunwales and stringers so there will be some bend in both directions with a small amount of twist.