Yep I taught my three how to swim. I didn't use any resources, I didn't know there was any available. But to be honest save your money, it was a really easy thing to do.
I taught my oldest at About 1 and a half. We went to the heated pool twice a day for two weeks. I put her in and got in with her. I showed her how to kick and how to paddle her arms. Then let her practice it. By the end of the first week she could jump in turn arounds and climb out alone. By the end of week 2 she could swim 7 meters doggy paddle head up or under water. That's was all I was aiming for so we then just made sure she had a chance to swim at least once a fortnight. When she was older and stronger about 3 I taught her to use a kick board ( you could do this much sooner!) perfected her kicks and then gradually taunt her to use over arm and breath. She is now 8 and the best swimmer in her class, beating the girl who does swim club twice a week in speed and confidence ( but not in grace
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I also taught her to dive the same way I remember learning it. Bend down, touch your toes fall in top of the head first. I taught all the kids at playgroup to dive too when their parents got frustrated they coudnt teach them. Took me 2 minutes to teach 8 kids! Then I taught her breast stroke and she learnt butterfly from a friend.
I taught the next two a bit less rigorously but they are still just as good age for age. My son could swim across a pool at 1 but had a scare at 3 and now he has a lovely lady teaching him to overcome his water fears, she is also doing some stroke correction with my middle child.
My advice overall. Read your books. Have self confidence, it's easy! Spend you money on advanced lessons and stroke correction much later. Keep it fun. Never use a pool ring (use noodles and kick boards) Use every opportunity to get in the water with your children. I believe this one point has more success than all the others. I alway find an excuse for a swim with them, if we visit and there is a pool I am getting in! Lol use arm bands on one kid if you have more than one kid learning at a time, just take the air out gradually.
Good luck!