Boat Pose is a posture that works the core muscles, mainly the abdominal muscles. These muscles are important for a good posture. They help support the back. Increasing our abs strength can help minimize or get rid of back pain.
In yoga, increasing the strength of our abdominal muscles, using postures such as Paripurna Navasana, will help us be stronger in most postures overall. But it is also part of bringing balance to our body. Use abs yoga poses to strengthen theses muscles, instead of relying only on general poses.
Boat Pose and other core focused poses help generate heat in the body. Practicing them is a good way to help the body warm-up at the beginning of a yoga practice.
Try keeping the spine long. As you flatten your back, lengthen the spine by reaching away from your sitting bones with your head.
This posture can be varied by holding the toes with your hands. In this variation, however, the abdominal muscles do not work as hard, since you are holding your legs with your hands.