This. When you're still, it literally feels like you're floating in space. I've been in tanks many times, and every time I feel like I'm spinning in outer space

This. When you're still, it literally feels like you're floating in space. I've been in tanks many times, and every time I feel like I'm spinning in outer space i.e you don't know which way is up or down. It's a totally unreal experience (think the highest level of meditation you've had now times it by 100), but sadly I've never achieved the feeling of OOB.