I remember being at the coast 1 year on the sea front and was bursting for loo.
Only loos open was disabled if you had key. After that and me not getting any younger. The need to go comes more often. So i bought 1 of these. Bargain for less than price of a beer. i ( I only recommend you only buy one of these for a back up. Or if you are like me and don't like pestering the official channels to get one.)