The following kit provides a tough workout, but also protects you from sunburn, windchill, rough rocks and aggressive creatures.
Before you attend a lifeguard beach training or boot camp, swim in your workout clothes to make sure they fit well and you enjoy swimming in them. It is important these clothes fit well. Nothing is more annoying than swimming clothes that don't fit or come off. You should be really comfortable in the water fully clothed.
Men: Swim shorts and a long sleeve thermal pullover for comfort.
Women: Full one piece swimsuit, or a sports bra with a thermal pullover and some kind of swim shorts. No bikinis, please.
Long unlined trousers with waist band or belt, a long sleeve top, and a windproof anorak or cagoule to keep you warm. You'll wear these over your swimsuit during the training.
Wear them all the time to protect your feet from sharp objects, even when swimming. Simple canvas shoes with drain holes are best. Socks help avoid chafing.
Fins are required for some exercises.
Get those with a full foot as they fit better.
Again, socks may avoid chafing.
You want to be able to see underwater for some of the exercises, especially in open water. Good fitting goggles or a snorkeling mask is useful for this. The hood avoids hair entanglement and jellyfish stings.
A poncho is useful as warm-up shelter during the break, as changing room, and for some training exercises on the beach and in shallow water.