Wouldn't you know it? A week before our family was scheduled to leave on a summer vacation to Belize, my son broke his wrist inline skating at an end-of-school party.

The local hospital didn't stock the special waterproof material for the cast because it's more expensive than plaster, so we were left wondering what we were going to do with our 11-year-old son. Our two weeks included lots of time on the beach, as well as snorkeling on the barrier reefs in the Caribbean.

Fortunately, we weren't the only family to enter summer with a limb in a cast, as there are products on the market designed to keep casts dry while submerged in the water.

One of these is Dry Pro Waterproof Cast Protector, which covers the cast in a vacuum seal. The giant blue "glove" is made of thick surgical latex that can stretch 600 percent without tearing. It kept my son's cast totally dry, even as he snorkeled amid stingrays and nurse sharks off the Belizean coast.

Measuring the cast to get the right size "glove" was easy. The glove is slipped on and air pumped out to create a vacuum seal so it can't fall or slip off. It should be worn no longer than 45 minutes at a time to prevent circulation problems.

Even though my son said he felt a little silly wearing what looked like a giant blue lobster claw, at least he could swim and participate in all the family activities on the trip. It also protects casts if you bathe, shower or need hydrotherapy.

The Wilmington, N.C., company also makes covers for half and full leg casts, as well as protectors for other medical needs such as peripheral catheters, prosthetics and ostomies.

Cost for the arm cover ranges from $35.95 to $39.95, depending on size, and leg covers range from $36.95 to $40.95.

The Dry Pro cast covers are available locally at some offices and pharmacies, including Hieber's Pharmacy, 3500 Fifth Ave., Oakland (412-681-6400, www.hiebers.com).

You can also order the covers online at www.drycorp.com.