How Tall Do Stakes Have To Be Off Bottom

I am going to drive a bunch of stakes into the bottom of the lake in 15 - 20 feet of water.

How tall / far off the bottom should the stakes stick? I've got a bunch of stakes that are about 4 1/2 to 5 feet tall. If I drive them 2 or 3 feet into the bottom they will stick up about 2 1/2 to 3 feet. Is that tall / far enough or do I need to get longer stakes.

Is longer better?

I try to cover at least fifty percent of the water column. If your putting in stakes in 15 to 20 feet and you only have 2 or 3 feet of stake in the column then chances are you will only get fish during the extreme water temps.(hot or cold) In our lake we can only drive the stakes between 6" and a 12" before we hit the hard pan.
Try your stakes in the 8' to 10' range and I think you better use what you have.
lol

I'm with fishordie, I like to cover at least 75% of the depth at winter pool. Anything deeper than 12' I usually cut trees.

Here We Put Them In 6 To 10' Of Water, Only Put Stakes 24'' To 30 '' High. Crappie Will Hold Close To The Bottom Most Of The Year Here. At Times They Will Suspend Just Over Them , But Most Of The Time 1' Above The Bottom.:)