The inside couple (always!) makes an arch and steps forward as
the outside
couple ducks through the arch into the center of the square.
The outfacing couple then does an automatic California
Twirl to complete the movement.
If the outside couple is taller
than the inside couple,
it is appropriate to "fake" the
arch - let go, then
reconnect after the other couple has
passed by.
For more detail on Dive Thru , click here: