These are generally helpful & approved Swimming Video Resources with commentary
Body Alignment
This swimmer asked for help with the two beat kick, but Terry’s assessment was, “He’s got bigger problems than that!”. Pay close attention to the part between 2:00 & 2:30 in Terry’s discussion of Body Alignment. He explains of forming “lines” along the body to swim straight & eliminate swaying and cross over. Swimming is so simple when you can feel it happen this way. This is my #1 focal point most times I swim, especially when I start to get fatigued in open water: