Casting over submerged cover ...
be it a brush pile, blowdown tree, totally submerged standing tree, stump bed, or whatever .... is quite productive, at times. Realistically, you can do this in depths of up to 15ft - with a long cast, and slow retrieve, using a 1/16oz jig (as long as the wind isn't blowing too strong). Shallower than that, and you can use a 1/32oz or smaller - deeper than that, and I would go up to a 1/8oz jig. Adjustments can be made, for deeper depths, by allowing the jig to fall before starting the retrieve (countdown method, as described by Mo'nBack)
Line size (diameter) is also a factor. Generally I'm using 6lb test mono, or 10/2 PowerPro braid ... and a weedless jighead. I like to cast over the top of the wood, first (not touching any wood), to pick off any fish suspended above it -- then I'll try and tic the top branches and end & side branches -- then probe down "inside" the cover. If I'm getting hits while "inside", and factors dictate that I "can" get directly above the cover - or "have to" get directly overhead, for a better presentation, then I'll start using the Vertical Casting method. Also, if I can't get to the cover for some reason, by casting, (like overhanging obstructions, high wind, dense surface cover, etc) then I'll "start" with the vertical approach.
One thing that I haven't mentioned lately, that goes along with casting over submerged wood, even with a weedless jighead, is what I call "taking a bow" to avoid getting hung on a branch. Even weedless jigheads can & will get hung, sometimes. This can be avoided, to an extent. When retrieving the jig, usually the line will swing back to you ... and you will notice it at the point where it enters the water (it will continue to get closer to you, as you reel in). When it stays in one spot, as you reel in, that indicates that the line is draped over something submerged in the path of your retrieve. As you continue to reel, eventually the jig will come in contact with that obstacle. As it does, and when the rod tip starts to bend down, a lot of people tend to try and "jerk" the jig over it. That works, sometimes, but quite often - they get hung. I try and avoid getting hung in the cover I'm fishing, so as not to have to break off - disturbing the cover, losing the bait, or alerting the fish to any unnatural conditions. I do this by "taking a bow" - with the rod tip.
In essence - I wait until the jig comes in contact, and the rod tip starts to bend ... then I drop the rod tip about 6" towards the jig, and in one fluid motion raise the rod tip up towards me about 12". This is not done fast, like a jerking motion ... but, more of a slow drop and lift motion. What this does (or seems to do) is allow the bait to fall away from the obstacle - then when you lift it back (twice as far as you let it fall away) the head of the jig "bumps" the obstacle, and "hops" up overtop of it. Well, most of the time, anyway. The reason I don't drop it down 6" and then lift it up more than 12" - is that I want the jig to clear the obstacle, but remain in the general area. I will work a tree top over, with this method, bumping and bowing and hopping the jig over multiple branches. Another reason I don't pull the jig back more than 12", or reel it back in (once I've cleared the branch) ... is because I've had numerous occasions where I've had a fish hit the jig, once it cleared the obstacle and started coming back towards me. In fact, it's happened often enough that I almost "expect" to get a hit, when "taking a bow" over a branch. ........... luck2ya .........cp :cool:
(thanks for the reference, Mo'nBack ! Hope the method works as well, for you, as it does for me)