Dave,
The "Devil's hole" is very popular with
experienced boat anglers ( no place for a 1st timer ), and guides. The hole you're thinking of, is probabley the Whirlpool, and would require a jet boat, and great skill to reach by boat. It may even be restricted. You
can access it ( via a long walk ), and the Devil's hole by shore. Most of the Lakers I hear of are caught in the lower drifts, below the powerplants. I've caught them just above Artpark, both from shore, and boat. The area in front of ( and just below ) the Lewiston launch, has a stretch of less turbulent flow, and sandy/gravel bottom. The Lakers are often found in this stretch. Some Walleye, as well.