drafting your own wool soaker cover with a diaper cut as a guide.

You can draft your own wool (or fleece)  soaker pattern using a diaper cut or pattern piece as a guide.

Here I have a boxboard soaker pattern laid over a diaper cut (newspaper) pattern .  you can use a pattern piece from a pocket, fitted, HF or cover.
Notice they are the same length.  Crotch width is also the same.  The leg curve at the back (up to the middle) is also the same.  Trace your back half of your diaper cut but cut off the wings.

The front of my soaker exactly matches my back.  Fold you pattern material in half and cut as one.

 And there it is.  Now if you'd like a soaked piece in your wet zone cut an oval that is more narrow then your crotch width by 2 inches (approx).  The length needs to be several inched shorter then the cover.  How much is personal choice.  I used white here so you can see it.

You likely want a leg cuff of about an inch or so.  Cut your cuff double your desired cuff height plus seam allowence.  This is cuz the cuff will be folded in half.

Cut your cuff length so that it fits the leg hole when cuff is stretched but soaker is not.  It will be a bit shorter then the leg hole.  It is best to measute this way as opposed to a specific length since each fabric will have a different stretch.  

Cut second cuff to match. 

* If your child has slender thighs stretch the cuff fabric tight.  If your child has thunder thighs, stretch it just a little . 

Your waist piece will also be twice your disered height plus seam allowence.  You likely want it at with a finished height of about 3 inches.  Stretch waist fabric length ways across the back of the soaker.  Mark this.  Since the front and back are the same double the amount plus seam allowence.  Like the cuff its best to decide in this manor rather then a pre set amount.  

And there you go.  I'll add a tutorial  . Sewing as soon as I have a chance to sew this lol.