My parents just built a 2 lift boathouse with adjoining 15x 25 pier. The old pier was made of cinderblock, and it was broken up and made to collapse inward with the new dock built over it. So now there's chunk rock underneath the new dock. It's in about 4-5 feet of water with little to no slope. How long before the bass will relate to this cover? It was completed last thursday. I'm thinking of running up there on my lunch break tomorrow and throwing a shaky head or a jig underneath it and seeing what happens.

My question is: how fast will bass key on new cover, and is there anything I can do to speed to process?

There's probably a bunch there now. Bass tend to cruise the shorelines and will stop anywhere they can find shelter and food. Sounds like you're sitting on a potential honeyhole!

How long until adult size bass take to relate to new structure and cover depends on when the prey locates there.

The only time that bass don't relate to prey is during the spawning period. Bass eat year around and the dock provides cover and structure for prey, some local bass will find it soon.

WRB

How close is deeper water to the dock, or how close to a channel?

Are you on a point, or on a bank that is straight?  any other features that would draw bass to your area?

Fastest way to draw predators is to have a food source in the area as mentioned.

    Dropping range cubes around the dock will draw lots of species of fish to the area.    

Range cubes attract minnows, cats, carp for sure.   Some brush would also help draw them in faster with more cover mixed into the shaded areas.

The pier is located in a shallow slew (can't spell it!) with an extremely slow drop to 10 feet in the very middle. Honestly there's not much redeeming qualities for this hunk of water but bass can be caught under the docks. I guess that is the only real cover in this area. It is a good crappie spot in spring as they come in the cove to spawn. This is weiss lake water! Going up there at lunch to see what's under there. Probably nothing but maybe some bluegill will be under the new dock and hungry for a rooster tail if all else fails

If this is Weiss Lake water then I am guessing that there should be a lot of grass near the structure.  Based on that lake, I also do not think it will be long before you find fish around it.   I have caught bass near nothing but a 5 foot stick stuck in the lake there.  From what you have described, that will be a great place to fish before too long.