I've heard about using a float, and say 10 feet of line let float to find and mark a reef. Ever do that?

Do you mean to mark a reef once you've found one? Or let the rig float in deep water until it stops moving because the sinker touched bottom?

The first is very common; the latter would seem to be a very time-consuming way to find a reef. Trolling a lure would be ever so much more practical and potentially productive.

Thanks Rocky, using a line to find a reef. I'd be trolling close by while watching the float.

Not to mention the fun of hanging the lure up on the reef and losing it!

I'm all for a depth finder and hand-held GPS to locate and re-locate. (Guess that might not qualify as low tech, though.)

We got to give them fish a fightin' chance? Right!

When fishing the Wolf River in Wisconsin during the white bass run, we would take a big bobber attached to 10 feet of line and hook it to the first fish we caught. It would swim back to the school, and we would follow it

Seems to me a depth finder is fair. Found structure in local lakes by running over it pre-depth finder. A little back and forth to see just which way the point ran. Just took a lot longer.

We would use a 15 ft piece of bailing wire with a 2 or 3 ft piece of chain to find oyster beds in the bay. It was easy just drop it over and drag it an you could feel them when the chain would hit them.

I don't know about where you are fishing, but on Eagle Lake in Ontario there are hundreds of reefs marked with a rock on a rope and a gallon bleach bottle or two tied on the other end.

Miles, mostly Wabigoon lake, just east of Eagle lake.

Then why don't you just mark it with a jug and a rock on a rope? That's legal in Ontario. If the problem is the finding of the reef then ask someone with a depth finder to mark it for you. Wabigoon has to be 100 square miles of water and I can't imagine fishing it without a depth finder. Or a GPS for that matter. Both of which can be had very cheaply nowadays. What am I missing here?