A dry suit isn't really dry if it leaks. Dry suits provide a watertight seal to divers, rafters, sea kayakers or others involved with water based activities. Testing a dry suit for leaks is possible either at home with a bathtub or at the beach with a few extra minutes and an assistant.
Fill the bathtub with water. Cold water is fine if you do not wish to use the energy for hot water.
Wrap the rubber bands around each ankle gasket -- the black rubber piece at the bottom of each leg on the dry suit. Wrap rubber bands at each wrist gasket -- the black rubber pieces at the end of the dry suit arms. Then wrap the neck gasket -- the black rubber neck collar -- with a rubber band. These rubber bands are not water tight, but prevent most leakage into the suit.
Dunk the suit into the bathtub water holding the wrists, ankles and neck just up above the water surface. Hold the suit in the water for five minutes. Watch for any air bubbles coming up from the suit. When noticed, pull the suit out of the water and circle the areas where the air bubbles originated so you can repair the small holes causing the leaks.
Put the dry suit on.
Enter the water up to waist height. Bend over and sit on the bottom of the water. Reach up and pry the neck gasket from your neck and allow the water pressure to force out any excess air from the dry suit. Sit back so your head and ankles are out of the water but your body is submerged.
Have the assistant watch for air bubbles rising up from the suit. If possible, have the assistant wear a diving mask and snorkel so he can watch underwater to spot the air bubbles rising form the suit.
Make the assistant circle the spots on the dry suit where the air bubbles originated.