Depth over crib? Foul??

[explodingvarmints]

Can anyone explain what "depth over crib" means? and for that matter, what is considered a "foul". The Navionics (or whatever chip) calls them out, but I have no Idea what they are..... I think "foul" means (i.e. don't hit it.) Or it could be a look out for fisherman on Jet Ski's.:D

[ESOX]

depth over crib means just that, the depth over the crib. (A crib is a structure of logs, sheet piling etc, usually filled with rocks that is used as a base for piers, break walls, or commonly around here, a water intake pipe for municipal water.

A foul is very shallow, or a transient depth like a sandbar. There is one spot in the northwest corner dumping grounds by the shipping channel that can change it's depth day to day. It can be 2' deep one day and 4 1/2' a couple weeks later, then back up to 3' in a week, without the lake fluctuating wildly.