Is the Island located in the Pacific or the Atlantic Ocean?

Written 25th March

Geography is certainly not my area of expertise, so maybe someone here can help me out with this…

Oceanic Flight 815 would have been flying over the South and North Pacific Ocean en route from Sydney to LA.

Ajira flight 316 would have been flying over the North Pacific Ocean in traveling from LA to Guam.

The Black Rock would have been traveling on the North Atlantic Ocean from the Canary Islands to The New World.

Now, I know that 815 was a couple of thousand miles off course…but ?????

So where is the island and how did these seemingly different courses intersect?