While taking care of business in the toilet, the unsuspecting woman was forklifted up in the air and carried to the other side of the venue.
Harbour master Rob Parsons told the BBC she must have "thought she had teleported".
"She got in the loo and then it was picked up and taken to the other side of the harbour with her in it. I think she was suffering from a bit of shock or she thought she had teleported across to the other side of the harbour."
She was uninjured but, we imagine, not impressed,
Perhaps most frightening was this statement from the director of portable toilet company Andyloos:
"It does happen quite a bit to be honest-I've done it a few times."