I have an older book that recommends using a deep-running crankbait weighing 1/4–3/8 oz and a medium-running crankbait weighing 1/4–1/2 oz. I’m not sure what depth ranges those would refer to—can you clarify what depths they likely meant?

The vintage diving crank baits never ran as deep as advertised.

Deep divers were 1/2 to 3/4 oz or heavier.

Medium divers generally 3/8 to 5/8 oz or heavier.

Never used anything lighter weight between 1960 to 2000.

What book ?

Tom

Are you sure you don't have it backwards?  Usually the heavier baits are deeper running.  IMO medium running is 4-8'.

4-8’ and 8-12’

Starting with my experience the deep diving plugs (crank baits) were;

Bomber 200, 300, 400 and 500 the number indicate length and looked like a bomb with metal lip running backwards. Probably caught more bass the original Bombers then any other crank baits.

Mud Bug very similar to Bomber with crawdad eyes added.

Bomber A series followed 6A and 7A, medium divers.

Bagley balsa lures lures the B series were outstanding with the DB3 Dredge diving to 25’ (sinking lure)

Norman were good deep divers DD14 and DD22, number are the depth that ran.

Poe Cedar 300 series, deep diver.

The above is I needed for decades.

Tom 

12 hours ago, WRB-2.0 said:

The vintage diving crank baits never ran as deep as advertised.

Deep divers were 1/2 to 3/4 oz or heavier.

Medium divers generally 3/8 to 5/8 oz or heavier.

Never used anything lighter weight between 1960 to 2000.

What book ?

Tom

One place I seen recently was here 

 

http://assets.espn.go.com/winnercomm/outdoors/bassmaster/pdf/BASSToday_SeasonalGuide.pdf

 

 

51 minutes ago, GoneFishingLTN said:

One place I seen recently was here 

 

http://assets.espn.go.com/winnercomm/outdoors/bassmaster/pdf/BASSToday_SeasonalGuide.pdf

 

 

Follows my old 1974Cosmic Clock and Bass Calender.

Crank baits never ran weights are similar to what Inposted.

Tom

PS, PM your email will send my Cosmic Clock and Bass Calendar.

Bandit 200 dives +/- 6', the 300 dives +/- 10'... both are pretty small.

How deep a lure can dive depends on how thick the line is, how much line is out and how fast it’s moving. The same lure on 17 lb mono cast out will not run nearly as deep as the same lure on 8 lb braid being trolled 100 feet behind the boat.