I was doing L&C in the water (but not in swimming pool) with my future wife.
As I am also big guy (265 lbs) lift and carry in the water is much easier. We did piggyback ride, front lift, cradle and that's pretty much it. I didn't convince my future wife to do shoulder ride in water. I don't think, she would agree because she doesn't have much core strength.
Once I was laying on bed, put my both legs on her shoulders, and she was doing some sit-ups. Maybe you guys have some more L&C exercise examples
With my weight I don't think, that any of L&C sex positions would work out.