Originally Posted by TIJoe
Not sure how you reached such a conclusion. I thought it was because Terry was trying to demonstrate how to spear steeper to get better balance in his teaching video. But when he swims in his normal stroke in open water, he spears a lot flatter. Same with Shinji in his most popular youtube video, many on this forum have commented he did not seem to spear that deep.
Firstly, salt water (also river/lake water) is denser than pool water so you float more. Take it to the extreme, you'd float on sand ie can't sink; and the other extreme you'd sink in air ie can't float.
I think that Terry is a bit less float-y than his daughter or Shinji so even in the pool it seems Terry needed (or demonstrated that many sinkers would need) to spear more deeply to help weigh the front down and pivot/see-saw the back half up. That's why he asked us to experiment for ourselves. His daughter and Shinji being more of a floatie seems clearly to need the lead hand in a more horizontal position for their proper balance. When swimming in open water Terry, and everyone else especially when wearing wetsuits, floats more therefore needs to spear more shallowly.
Also as you can see in Easy Freestyle Superman glide and particularly laser lead, legs can/will sink unless you use flutter kick which in this case is not much to do with speed but with the crosswise vector force of pushing down on the water to help float the back half up.
Anyway, this is just my view so far -after a lot of thoughts trying to understand the how's and why's. Cheers