Fiberglass pools have a supersmooth gel coat finish that's extremely durable and stain resistant. Unlike concrete, fiberglass pools are nonporous, so they tend to use fewer chemicals and harbor less algae. However, fiberglass pools come in fewer sizes and shapes than concrete or vinyl pools. And the huge molded pools must be shipped via truck, which are often forced to take long, circuitous delivery routes. "The transportation of oversized loads is regulated by individual states," explains Suzanne Barrows of the Association of Pool and Spa Professionals. "Therefore, truckers will often have to drive around several states to deliver a fiberglass pool." How a fiberglass pool gets to your house isn't your responsibility, but there must be adequate space in your yard for the crane to drive to the pool site. All three types of pools—concrete, vinyl and fiberglass—are available nationwide. However, some types are more prevalent than others in certain regions. The flexibility of fiberglass and vinyl liners makes them ideal for very cold climates where winter freezing and thawing cycles can damage a rigid concrete structure. Vinyl pools are sold in most areas, yet fiberglass is most popular in the south. Not sure which type of pool is best for you? Rely on the expertise of local pool contractors. If they're all installing the same type of pool, it's probably for a good reason (it often has to do with the local climate and soil conditions).