Two men plucked from Western Australian ocean in hospital

A man is in a critical condition in hospital after he and another man were rescued from waters off Perth's north.

The emergency beacon on their boat was activated at 10am on Monday, about 3.7km west of Two Rocks.

Surf Life Saving said around 1.15pm rescuers found the men in the water but wearing lifejackets.

Police said one of the men was unconscious and remains in a critical condition.

Both men, aged in their 30s, have been taken to Joondalup Health Campus.

Police said the 5.8m vessel was purchased by one of the men on Sunday.

It was earlier reported that a suspected "boat blast" was responsible for the accident.