Serious Sam: Siberian Mayhem

For those who prefer a little more in depth written guide, here is my suggestion.

The third level Siberiade is the first time you encounter both sentry towers and hoverboards.

The first spot you can get a hoverboard is as a reward for completing the sidemission of the Third level. The sidemission can be found in the first open level section of Siberiade behind one of the bases with the pipepuzzles.
In this open level area, there is a secret hoverboard as well between the second group of Oilpumps and the objective marker on a small hill which can be accessed from the backside.


If you are already past this point you can find a secret hoverboard between the first and second sentry tower. If you follow the road along the first tower, the road will fork. Follow the road to the right and drive on the road until you see a cabin with a scarecrow. On the otherside of this cabin is a secret hoverboard. In front of you directly is the second tower. So use it to take the tower out.

After you cross the bridge with the puzzle you can either shoot or solve, you come a cross an ATV. A guy warns you over the radio that there are sentry towers in the area ahead. You are now in the right spot.

Once you hear the tower blearing and see circles appearing on the ground. Jump off the atv, select the hoverboard gadget using the weapon wheel() and drop it using . Keep moving around, shoot the miniguns on the side to take those out. Not necessarry but recommended. Once the tower drops it shielding to vent, shoot the core until destroyed.

Should take a couple seconds on tourist or easy and the achievement is yours!