Small cruising boats have also been developed for trailing, or towing, behind automobiles. The increased use of construction materials such as plywood, aluminum, and fiberglass has been a great help in promoting trailing. A boat with seams could not be left out of the water too long or it would dry out and leak when put back in the water. Solid hulls of the above materials can be left out of water indefinitely without harm. The boats have become more __________.

- unpredictable

- leisurely

- graceful

- durable