The Avalon tank is worked in the round from the bottom up. It is split at the armholes to be worked flat. You may find that you need to go down in needle size when you begin working in rows (I did).
The style of this tank is meant to be cropped, hitting just at the waist. If you wish to have a longer silhouette work extra length before beginning the waist decreases. Remember, this may require additional yardage!