Pull - Focus will be on learning to 'catch' the water with your forearm and pull yourself through the water. If you feel your lats (the muscles under your arm pits that go down the side of your back) engage, then you are starting to get it. If your shoulders are tired, then you are still using too much shoulder and not enough lats.
Depending on where you are in your off-season training, this is your weight training day. Use this day to also get additional 'Core Strength' exercises in for a total of 2-4 sessions per week. See Core and Strength Guidelines for more information.