Character partially penetring object

I have a shark with an armature for a swimming action. The armature moves forward with space bar. I’m doing that by setting the Linear Velocity because I read somewhere not to set dLoc on dynamic objects. However I’m having trouble with it either going through objects or partially penetrating them.

If armature and shark are static then they simply pass through the surroundings. If I make the armature dynamic and check Collision then it goes halfway into an object, say a cube, before stopping. I’ve locked the location and rotation on the cube because I don’t want it to get pushed around. Am I doing it right? Is there some way to stop it going part way into the cube? I’ve set gravity to 0 so it doesn’t just drop like a stone when I hit P.

you can not put to a armature dynamic(I’m not entirely sure), add a cube, scale the cube to the size of the shark, parent the armature to the cube, put the cube to dynamic and put your logic to the cube for move. Sorry english.

Thanks, I’ll give that a try.