four blocks area lake of the woods

Just returned from fishing LOW, south section of the lake was good for walleye & sauger, NW Angle was great for both species. Fished the reefs off little oak island, and a place called, the hole, by the locals. Jigging with minnows produced all the fish one would want to catch in a day. First time fishing the Angle, have been on the south shore several times. Seen some reports mentioning the four blocks area. Where is this located?

It’s an island south and a little west of Oak.