Jerry was standing in the water half as deep as his height.

[tufguy]

1) Jerry was standing in the water half as deep as his height.

2) Jerry was standing in the water deep up to his chest.

3) Jerry was standing in the water with his head and chest out of the water.

Please check my sentences.

 

[Raymott]

"Jerry was standing in [the] water up to his waist." (... if you want the midpoint of a normal human.).

 

[GoesStation]

For number 2: Jerry was standing in chest-high water.

 

[emsr2d2]

You could say "Peter was standing in water up to his chest". Don't use "deep" in that sentence.
You could say "Peter was standing in the water. It was chest-deep."

 

[Skrej]

A condensed alternate could be "Peter was standing in waist-deep/chest-deep water."