Great Swimming

Compared to running and cycling, technique contributes more to swim speed than added effort. A swimmer's main adversary, aside from fellow swimmers that kick off their goggles and generally beat them up, is the water itself. Specifically, the density of water. In order in increase swim speed a swimmer must trick the water to flow around them instead of against them. The harder a swimmer push against the water, the harder the water pushes back and fatigues the athlete. Here are a couple of videos that show effortless swimming. The key is "effortless power".

Swimming should look and feel like this:

A great video of Terry Laughlin, the founder of Total Immersion Swimming, explaining the philosophy of his technique: