Does concrete float? For the hundreds of civil engineering students at the annual National Concrete Canoe Competition, the answer is "yes."

Teams representing 23 schools vied to design, build and race canoes made of concrete. Some vessels were as long as 22 feet and weighed as much as 180 pounds. A wooden canoe of the same size weighs about 40 pounds.

Alicia Welling, manager of the California Polytechnic State Univ. team, says the trick to making concrete float is to mix it with glass bubbles and other lightweight objects.

Welling says the three-day American Society of Civil Engineers event gave students practical experience in finding creative engineering solutions and working as part of a team.