The name probably originated as a way to describe the fragile, thin nature of the boats, especially in the days before strong composite materials such as Kevlar and carbon fiber.
Shells can range in size from a one-person boat to one carrying eight rowers.
Oars Not paddles. Rowers propel the boat by pulling on either one or two oars each. The shells, which are very skinny, are balanced upright by the oars, so a disruption in the balance, such as catching a crab, can cause the boat to tip over. Sometimes, especially during races, getting an oar caught in the water can cause the handle to hit the rower in the gut or chin, knocking him out of the boat. Crew Members of a boat squad.