Swimming is my hobby.Can you swim a ocean?
Well since you need to coordinate your movements of the limbs and the body to swim, no, i am a terrible swimmer!
OK ,what are the swimming techniques?
only slightly less dense than water, water supports the weight of the body during swimming. As a result, swimming is “low-impact” compared to land activities such as running. The density and viscosity of water also create resistance for objects moving through the water. Swimming strokes use this resistance to create propulsion, but this same resistance also generates drag on the body.
Hydrodynamics is important to stroke technique for swimming faster, and swimmers who want to swim faster or exhaust less try to reduce the drag of the
high school swim team.
"At age 13, I discovered I really enjoyed the solitude of doing laps," Laughlin told author Tim Ferriss. "Just through doing the laps to earn my 50-Mile badge, I turned myself into an OK swimmer, certainly not one with any sort of efficient technique, but one who could swim a mile a day." 
"After a modest high school swimming career in which he never qualified for the New York City Catholic High School Athletics Association championships and swimming four years at