That's more or less what I was saying, Vince . . .
The Pacific tectonic plate travels northwest, but the hot-spot you mentioned that exists beneath Hawaii does not seem to move with it. Though there was a period of relative dormancy between the two formations (possibly a time called snow-ball Earth?), but the now extinct and much-eroded Midway Chain and the quite active Hawaiian Chain appear to have been formed from the same source, with likely Midway being the larger formation (initially).
Currently, measured from base to peak, I believe I read somewhere that the Big Island is actually the largest mountain on Earth.
Dan