Human-powered watercraft in the context of "Marine propulsion"

Rowing is the act of propelling a human-powered watercraft using the sweeping motions of oars to displace water and generate reactional propulsion. Rowing is functionally similar to paddling, but rowing requires oars to be mechanically attached to the boat, and the rower drives the oar like a lever, exerting force in the same direction as the boat's travel; while paddles are completely hand-held and have no attachment to the boat, and are driven like a cantilever, exerting force opposite to the intended direction of the boat.

In some strict terminologies, using oars for propulsion may be termed either "pulling" or "rowing", with different definitions for each. Where these strict terminologies are used, the definitions are reversed depending on the context. On saltwater a "pulling boat" has each person working one oar on one side, alternating port and starboard along the length of the boat; whilst "rowing" means each person operates two oars, one on each side of the boat. On inland waterways, the opposite applies, with "rowing" being where each person in a crew works one oar and "sculling" (especially in sport rowing) involves each participant using a pair of oars. In a maritime setting "sculling" means propelling a boat with a single oar operated over the stern.

A paddle is a handheld tool with an elongated handle and a flat, widened end (the blade) used as a lever to apply force onto the bladed end. It most commonly describes a completely handheld tool used to propel a human-powered watercraft by pushing water in a direction opposite to the direction of travel (i.e. paddling). A paddle is different from an oar (which can be similar in shape and perform the same function via rowing) – an oar is attached to the watercraft via a fulcrum.

The term "paddle" can also be used to describe objects of similar shapes or functions:

A kayak is a small, narrow human-powered watercraft typically propelled by means of a long, double-bladed paddle. The word kayak originates from the Inuktitut word qajaq (IPA: [qajɑq]). In British English, the kayak is also considered to be a kind of canoe.

There are countless different types of kayaks due to the craft being easily adaptable for different environments and purposes. The traditional kayak has an enclosed deck and one or more cockpits, each seating one occupant or kayaker, differentiating the craft from an open-deck canoe. The cockpit is sometimes covered by a spray deck that prevents unwanted entry of water from waves or splashes. Even within these confines, kayaks vary vastly in respect to materials, length, and width, with some kayaks such as the sprint kayak designed to be fast and light, and others such as the whitewater kayak designed to be sturdy and maneuverable.

Paddling, in regard to waterborne transport, is the act of propelling a human-powered watercraft using at least one hand-held paddle, or paddling directly with the hands (without a paddle) as in traditional paddleboarding (also known as prone paddleboarding). The paddle, which consists of one or two blades joined to a shaft, is also used to steer the vessel via generating a difference in propulsion between the two sides of the watercraft. The paddle is not connected to the boat, unlike in rowing where the oar is attached to the boat.

In paddling sports such as canoeing and kayaking, the characteristics that are most important include "dynamic balance, core stability, pulling power, speed, endurance, stature, and rhythm".

Boat building is the design and construction of boats (instead of the larger ships) — and their on-board systems. This includes at minimum the construction of a hull, with any necessary propulsion, mechanical, navigation, safety and other service systems as the craft requires.

The boat building industry provides for the design, manufacturing, repair and modification of human-powered watercrafts, sailboats, motorboats, airboats and submersibles, and caters for various demands from recreational (e.g. launches, dinghies and yachts), commercial (e.g. tour boats, ferry boats and lighters), residential (houseboats), to professional (e.g. fishing boats, tugboats, lifeboats and patrol boats).