The mainsail is the largest sail on a sailboat and is responsible for generating the majority of the forward propulsion. It captures the wind and converts it into thrust, propelling the boat forward.

Sculling is a rowing technique where both arms are used simultaneously to pull the oars through the water. This technique is commonly used in recreational rowing and is characterized by its smooth and continuous motion.

Reefing is a technique used in sailing to reduce the sail area when wind conditions become too strong. By reducing the sail area, the boat becomes less susceptible to being overpowered by the wind and is easier to control.

Skiffs are lightweight and maneuverable boats commonly used for recreational rowing. They are popular for their stability and ease of handling, making them suitable for beginners and experienced rowers alike.

The coxswain is responsible for steering the boat during a rowing race. They sit in the stern of the boat and use a rudder to control the direction. The coxswain also communicates with the rowers to set the pace, rhythm, and tactics of the race.

Tacking is a sailing maneuver that involves turning the boat into the wind. This is done by bringing the boat's head up into the wind and then shifting the sails to the opposite side of the boat. Tacking allows the boat to sail upwind.

Feathering the oars in rowing involves rotating the blades of the oars so that they are parallel to the water during the recovery phase. This reduces drag and allows the rower to recover the oars more quickly and efficiently.

Catamarans are known for their speed and maneuverability due to their twin hulls. The twin hulls provide stability and reduce drag, allowing catamarans to sail faster and more efficiently than monohulls.

The mast step is the point on a sailboat where the mast is attached to the deck. It is typically a reinforced section of the deck that provides support and stability for the mast.

Sweep rowing is a rowing technique where a single oar is used to propel the boat. The oar is held in one hand and is swept through the water in a continuous motion. Sweep rowing is commonly used in competitive rowing and is characterized by its powerful and efficient stroke.

The daggerboard is a retractable blade that is used to prevent the boat from capsizing. It is typically located in the center of the boat and is lowered into the water when sailing upwind. The daggerboard helps to keep the boat from being pushed sideways by the wind.

Rowing shells are lightweight and narrow boats specifically designed for competitive rowing. They are characterized by their long, sleek hulls and are rowed by a crew of rowers who sit in a line facing backward.

The sheet is the rope that is used to control the mainsail in sailing. It is attached to the clew of the sail and is used to adjust the angle of the sail to the wind.

Gybing is a sailing maneuver that involves turning the boat away from the wind. This is done by bringing the boat's stern up into the wind and then shifting the sails to the opposite side of the boat. Gybing allows the boat to sail downwind.

The rudder is a flat, underwater surface that is used to control the direction of the boat. It is typically located at the stern of the boat and is connected to the tiller or wheel. By turning the tiller or wheel, the rudder is moved, which causes the boat to turn.