Boats have a number of relevant specifications, but the length of a boat varies based on how it's measured. The overall length measurement includes the pulpit, which is the railing at the front of a boat. The length on deck doesn't include the pulpit.
The registered length of a boat, which is important on regulatory documents, averages the length on deck and the length on the waterline. People considering buying a boat need to ensure that advertisements specify which measurement they're relaying.
A boat's specifications also include its weight, which is essential for determining how the boat performs on the water. A boat's builder weight represents how much it weighs with no water in any tanks; this measurement is often called the dry weight of the boat. Documents also often describe the boat's displacement, which is a measure of how much water the boat moves.
When describing speed boats and other performance boats, advertisements sometimes list a maximum speed. However, potential buyers should be cautious when evaluating these numbers because the large number of factors that can affect a boat's speed make this value difficult to calculate. Since there's no standard way to calculate a boat's speed, there's no guarantee that two manufacturers calculate this value the same way. As a result, many manufacturers don't include this specification.