Most people who have never floated before will say that they are claustrophobic. Of course! However, in reality, floating is much different from being locked in a coffin, or getting an MRI.
The door is never locked and opens easily. The float space is actually much larger than you would think. You can actually stand up in our larger float room (over 9 feet tall). You are more than welcome to float with the door open and lights on the whole time if you please. Even when closed, again, the door is never locked, and you can easily open it and come in and out as you please. You are in total control the entire time.