As divergence is defined as constructive plate boundary with opening in between the two slabs of tectonic rock being an heavy and oceanic plate the divergence is found mostly in where the new lava flows are being created and the newer rock are thus located near to the surface of the ridges as a result of the upwelling of hot molten lava from the magma chambers below.
Other examples being the mid-Atlantic ridge, red sea ridge, and eastern pacific rise.
And other popular ridges in the world that have lava flowing from the base and thus demarcate the divergent boundaries with continental crustal movement based on some sentiments form below, as slab push and slab pull.
Why doesn't it follow a straight line? Why do we need it? The International Date Line serves as a beginning and ending point for the world's time zones. The line moves in jagged directions through the Pacific Ocean in order to keep certain island nations together.