The American Academy of Pediatrics does not include swimming in its checklists of developmental milestones for children, but that doesn't mean that swimming isn't an important life skill. The AAP recommends swimming lessons for children 1 year old and older, with instruction becoming increasingly formal around the age of 6 years. The Red Cross has a water skills and safety chart that includes milestones for each swimming level.
Level One Milestones
Level one milestones are about the same for preschool swimmers and swimmers aged 6 years old and up. They include getting in and out of the pool safely, blowing bubbles through the mouth and nose, floating on the back, treading water using hand and combined arm and leg motions on the front and back. Children must be able to meet these requirements before moving onto to level two.
Level Two Milestones
Again, level two milestones are just about the same for the preschool level swimming classes and the classes for children 6 years old and up. Children must step into the pool, switch from front to back and back to front floats, tread water using arm and leg actions and bobbing. The one difference between each age group's level two milestones is that those in the 6 years old and up group must also be able to submerge themselves under the water and hold their breath.
Level Three Milestones
This is the final level for children under 6 years old and the middle level for children over 6 years old. For both age groups, swimmers should be able to jump into the pool from the side, tread water, bob, recover from a float to a vertical position and do a back float and glide. Those in the older age group should also do the front crawl and elementary backstroke, use flutter, dolphin and scissor kicks and go into the water headfirst from sitting and kneeling positions.
Level Four Milestones
This level is only for swimmers 6 and above. Children should be able to dive into the pool from the compact position, swim underwater, perform the front and back crawl, backstroke, breaststroke, sidestroke and butterfly stroke. Swimmers also work on turns from the front crawl and the backstroke as well as treading water using two kinds of kicks.
Level Five Milestones
This is the most advanced level of swimming instruction; students at level six focus on particular skill sets such as advanced diving, fitness or water safety. At level five, children learn to do a side dive and then begin a front stroke, tuck and pike surface dives, all the strokes and doing flip turns while swimming.