Hello, I have just created a Fish Mob, And when It is swimming, it keeps bobbing up and down in the water...

Can anyone help me please?

 

Here is my EntityFish code:

 

 

public class EntityFish extends EntityWaterMob {

    private int randomMotionVecX;
	private int randomMotionSpeed;
	private int randomMotionVecY;
	private int randomMotionVecZ;

	public EntityFish(World par1World)
    {
     super(par1World);
     tasks.addTask(0, new EntityAIMoveToWater(this, this.worldObj));
     tasks.addTask(1, new EntityAISwimmingFish(this));
     tasks.addTask(2, new EntityAIPanic(this, 0.38F));
     tasks.addTask(3, new EntityAIWander(this, 0.3F));
    }
    
    protected void applyEntityAttributes()
    {
        super.applyEntityAttributes();
        this.getEntityAttribute(SharedMonsterAttributes.movementSpeed).setBaseValue(1D);
        this.getEntityAttribute(SharedMonsterAttributes.maxHealth).setBaseValue(10.0D);
    }
    
    public boolean isAIEnabled()
    {
        return true;
    }

public boolean canBreatheUnderwater()
    {
        return true;
    }

protected boolean canDespawn()
    {
        return true;
    }

protected Item func_146068_u()
    {
        return Items.fish;
    }

public void writeEntityToNBT(NBTTagCompound par1NBTTagCompound)
    {
        super.writeEntityToNBT(par1NBTTagCompound);
    }

public void readEntityFromNBT(NBTTagCompound par1NBTTagCompound)
    {
        super.readEntityFromNBT(par1NBTTagCompound);
    }
    
    public boolean getCanSpawnHere()
    {
        return worldObj.checkNoEntityCollision(boundingBox);
    }
    
    public boolean isInWater()
    {
        return this.worldObj.handleMaterialAcceleration(this.boundingBox.expand(0.0D, -0.6000000238418579D, 0.0D), Material.water, this);
    }{
    
        if (!this.worldObj.isRemote)
        {
            this.motionX = (double)(this.randomMotionVecX * this.randomMotionSpeed);
            this.motionY = (double)(this.randomMotionVecY * this.randomMotionSpeed);
            this.motionZ = (double)(this.randomMotionVecZ * this.randomMotionSpeed);
}
}
}

The Problem should be some of the AIs you are using. I guess EntityAIPanic, EntityAIWander or EntityAIMoveToWater try to swim on the water rather than diving in it so they wont drown.