Who make a square bill CB that will dive 12' to 14'

No one that I know of. Square Bills are desinged not to go deep.
Far as I know 4 feet would be max.

You might just want to shave the lip down yourself. It might take a little bit to tweak till you get the desired effect, but never hesitate to try new things. You might end up making a pretty nice bait.

Fred Arbogast 1 oz Mud Bug

You can find some baits with long coffin bills if that will work for you.

+1
Those things can be awesome.

+1 on the coffin bill suggestion

Rapala has the coffin bills in the flat series that work great.

H20 doesnt have one?

Not in a square bill, no.

Try Hot Lips express deep diver. They 're not square but they have a bulge half way down the long bill to bump it around obstructions. It gets DEEP.

Rapala makes the closest thing your gonna find to a deep diving square bill i tell you a deep divn crank bait that i like and has better action than the dd 22's of the world is lucky craft d 20 not a square bill but out fishes the rest of the deep plugs on a lot of different lakes for me i do it day in and day out.

bandit makes a coffin lip crankbait too i believe

Don't know if they still make them or not, but a local sporting goods store is selling out some Spro cranks on clearance. Some were called a DD30 I think it was but said they dove to 12-15'. They are a square billed crankbait. I bought some for a friend. He used them a couple of weeks ago on the Bend. Said he never caught any on them (or any other cranks he threw), but said they didn't seem to hang up as bad as the other deep divers he threw. Again, don't know if they still make them or not-but they did at one time.