Butterfly - Underwater Weapon
Ultimately, the sport of competitive swimming is about racing. Finding what skills, or weapons, work best for you in those races is key to winning.
Why do it:
When you discover a faster way to get through the water, basically... you should use it. Many swimmers think swimming fast is about swimming, when sometimes it can be about NOT swimming. This example will be how to use underwater dolphins off turns as your weapon of choice.
How to do it:
1) Find a teammate of about your speed to race (you can actually do this everyday in practice).
2) Determine a distance you're going to race, and start to make up some rules.
3) The first race will be with both swimmers starting to swim early (like many young swimmers will do on the last lap of a 100 or 200 fly).
4) The second race, one of the swimmers will be allowed to use the underwater dolphin to see if they can gain an advantage.
5) The third race, both swimmers will be allowed to use whatever they want to try to win the wall.
How to do it really well (the fine points):
Remember, winning the walls isn't just about going further than the other swimmer, it's about checking the momentum shifts. If you're faster than the other swimmer underwater, use it. If you're a faster swimmer... use that. The most important thing is discovering which weapons work for you.