upside down condos

I am wanting to put some condos under a houseboat dock and one or two boats specificaly. The problem is the water under them is 50 to 55 feet deep. I was thinking about making some stand up crappie condos and hanging them (I dont know exactly how yet) from the bottom of the boat dock. By doing this I would always have a condo at the exact same depth below the water surface. My question is do you think this will work. Would one expect crappie to gather in a brush pile thats 10 feet deep at the top but over 55 feet of water
If this works I have been rained out, froze up, blown off, the lake for the last time. Not to mention the posibility of a nightstalk while your watching the big game or grilling out.

Make them out of PVC, put pvc in about 50 pounds of cement, put a Poly rope about 25 feet long in the wet base along with the PVC and hang it from the pier.

I did exactly that with small oak's 4 year's ago and they hold fish year round,if you could place a few in shallower water up and down the dock you will have some great fishin.I took two tree's about 15' long and wired them together so they will cover 30' deep and put a block in the top of the deepest tree then about 6' of wire to the base of the other tree and secured it to a brace in the corner of the boatslip.Trim a few of the longer and bushier limb's and use heavy copper wire and you will have cover that will produce for year's to come.

on a local lake - one of the Marina's (floating) used to hang Cedar trees off the back walkway. They'd take a 8-10ft tall Cedar and tie a concrete block off the base a couple of feet. Then tie to the upper 1/3 of the trunk and tie that off to the dock. Cedar top was never more than 3ft under the water. And this dock was in 85ft of water, at full pool (on the back walkway) !! You could see Crappie, Bluegill, and Bass hanging around it ... most any day you checked on it.
Most of the time ... "Vertical Casting" a 1/16oz white or chartresuse marabou jig alongside the Cedar would produce. The Crappie didn't have to get "inside" of the tree, because they had the overhanging dock for security, so you didn't have to cut out any portion of the tree. Shad never really hung around it, but minnows & fry did ... and that's what the other fish were keeping an eye on !!
Back in "the old days", when some of the Marinas had "fishing rooms" (heated with the old coal stove), this is what they would do around the inside of the open floor (inside the room). Because this lake can rise/fall as much as 25ft in a season ... putting brush & trees on the lake bottom, under the docks, wasn't productive. The Marinas (docks) were on 45deg slanted banks, and had to be let out/pulled in by cables to adjust to the rising/falling water level. You could be fishing in 15-25ft of water on one trip ... and the next time the water could be 25-40ft deep, under the same part of the dock. Having the Cedar trees "hanging", was a very productive (& cheap) way to insure that Crappie were going to be around most of the time.
I see no reason why your idea would not work, just as well ... cp :cool: