In Sanskrit Nauka means yacht or boat. In this asana body gets shape of yacht so, it is called as Nauka asana.
There are two versions of Noukasana practiced in
(1) prone position and
(2) supine position.
The difference between these two is that in supine Noukasana muscles of abdomen and stomach are contracted and in the prone position Noukasana the muscles are stretched.
Noukasana (supine position)
Position of Readiness
Lie down on your back. Keep the whole body loose and in a straight position. Palms can on the floor. Do not use any pillow under your head. Keep your eyes gently closed with the facial muscles relaxed and breathe deeply and slowly through the nostrils.
Inhaling, slowly raise your legs together; simultaneously, raise the head and trunk also, and stop at 45° angle(with the floor) . Hold breathe, and in the same position raise the shoulders and the back. Hold the toes of the legs with both the hands. Continue normal breathing. Keep the knees straight or else the expected pressure on the organs is not achieved. In this position it is always difficult to maintain the balance of the body but with practice one can achieve the steady posture. If initially you can't catch the toes then hold the legs at ankles but don't bend the legs in knees. While returning to the original positions first place your trunk and head on the ground. Now slowly bring down your legs and hands and lie on the ground as in the first position.
It helps in reducing the size of belly by the contraction of the abdomen from both the sides. Organs like lever, intestines, pancreas, kidneys etc. stimulated with pressure which improves its functioning. It is very useful for Diabetes and Dyspepsia.
Though this asana is useful for abdomen problems, people who have been operated on abdomen should not do this asana. Those suffering from hypertension, heart disease an lumbar spondilitis should consult an expert before practicing it