Showering ettiqute for lifeguard training

What is the expectation for lifeguards who are in training, I'm from uk and after being in the water during training from those who have, do you usually strip naked to shower in the usual communal showers of a swim pool or do you and the others keep your trunks on? I'm 22 year old male about to start soon, is this a big deal stripping off or should I keep myself covered?