Bobbing boxes!?

[The Hash Weasel]

In a part of the map I'm making,I have some crates half submerged in some water.They look pretty stupid just sitting there,doing nothing in the water...
Anyone have any ideas as to how I can make them bob up and down in the water or have a fairly convincing kind of movement to make the box's look like there actually floating?
Also,in the properties menu,under movement,what does the 'buoyancy'section do?
Does it make things sink or float perhaps?

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Hey relax,guy!

[obi wan kaNEWBIE]

<dredging my memory>...try going into the MOVEMENT section of a boxes' class and set PHYSICS to 'floating'. I've done this, but it's been a while.

[The Hash Weasel]

I went to the physics class under movemet,and there is no 'floating' theres falling,swimming walking,and a buncha others.
I tried a few of them and they dont do anything anyways.I tried mucking with the desired rotation and rotate to desired and some values for it,but that did nothing either...anyone care to give this problem another shot?

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Hey relax,guy!