Best Units For Measuring A Boat: Feet, Inches, Or Meters?

Measuring a boat is a complex task that requires careful consideration of various factors. The length, width, and height of a boat are all crucial aspects that need to be measured accurately for docking, storage, and compliance with maritime regulations. The length overall (LOA), beam, and draft are the primary measurements that boaters need to understand to ensure safe and efficient navigation. The LOA is measured from the tip of the bow to the stern's farthest point, excluding any removable parts like outboard motors or attachments such as swim platforms. The beam, or width, of the boat is calculated at its widest point, and the draft refers to the vertical distance from the waterline to the bottom of the hull. These measurements play a vital role in docking, stability, and determining the minimum water depth required to navigate safely.

Length

LOA refers to the boat's longest span, from the tip of the bow to the stern's farthest point, excluding removable parts like outboard motors, swim platforms, or wakeboard towers. This measurement is crucial for determining dock space, storage requirements, and marina slip availability. It also plays a role in regulatory compliance and safe navigation.

The length on deck is similar to LOA but excludes protrusions and typically accounts for only the length of the deck. This measurement can still be used to approximate the boat's total size.

Waterline length (LWL) refers to the length of the boat with respect to its current waterline. It considers only the submerged portion of the hull, so it is usually shorter than LOA. LWL is essential for performance measurements, such as racing.

Accurate length measurements are vital for docking, storage, and compliance with maritime regulations. They help determine the required safety equipment, registration, and travel permissions in certain waters. Additionally, precise length measurements aid in route planning by ensuring compatibility with water depth, bridge clearances, and marina sizes.

Width

The width of a boat is known as its 'beam'. This is the boat's widest point, measured horizontally across the vessel. It is important to know the beam width for docking and stability assessments, as well as for selecting appropriate trailers, dock spaces and marina slips. It is also essential for safe passage through narrow channels and locks, and for optimising boat transport logistics.

To measure the beam of a boat, stand inside the boat and run a measuring tape from the left to the right side at the widest point. The average width of a boat is 8 feet.

The beam is one of the boat's primary measurements, along with Length Overall (LOA) and Draft. These three measurements are crucial for safe docking, storage and navigation.

Height

Measuring the height of a boat is essential for several reasons. Firstly, it helps determine the boat's draft, which is the distance between the waterline and the bottom of the vessel. A boat's draft influences its ability to navigate smoothly in shallow waters. The taller the boat, the more draft it will require. Therefore, knowing the height of the boat is crucial for understanding its performance characteristics in different water depths.

Secondly, measuring the height of a boat is crucial for safe docking and storage. The height of the boat determines the amount of space required, especially when docking in a marina or storing in a covered facility. Accurate height measurements ensure that the boat will fit within the designated space without causing damage to the vessel or its surroundings.

When measuring the height of a boat, it is important to consider two key aspects: the distance from the beam's highest point to the bottom-most portion of the hull, and the freeboard, which is the distance from the deck to the waterline. These measurements provide critical information about the boat's overall profile and its ability to navigate different water depths.

Boat owners and shipwrights typically use tape measures to determine the height of a boat. It is important to ensure that the tape measure is placed correctly and follows the contour of the boat. For larger boats or more complex measurements, laser distance measurers can be employed to achieve greater accuracy.

In summary, measuring the height of a boat is vital for compliance with maritime regulations, safe navigation, and efficient docking and storage. By taking precise height measurements, boat owners and operators can make informed decisions regarding the vessel's suitability for various environments and ensure a safe and enjoyable boating experience.

Speed

When it comes to speed, boats are a little different from other vehicles. While cars, trains, and most other vehicles measure speed in miles per hour (mph) or kilometres per hour (kph), boats use a different unit: the knot.

A knot is a unit of speed equal to one nautical mile per hour, which is approximately 1.15 mph or 1.852 kilometres per hour. So, if a boat is travelling at a speed of one knot, it is covering a distance of one nautical mile every hour.

The nautical mile is slightly longer than a standard mile, with one nautical mile being equal to about 1.1508 miles. This difference is not a coincidence; the nautical mile is derived from calculations based on the Earth's longitude and latitude coordinates, with one nautical mile equal to one minute of latitude as measured from the Earth's equator. This makes it a very useful unit for sailors, as it is compatible with the coordinates they use when travelling.

The term "knot" has an interesting history. It dates back to the 16th or 17th century when sailors used a "chip log" or "common log" to measure their ship's speed. This device consisted of a flat piece of wood or a wooden board attached to a rope with knots tied at regular intervals. The sailors would throw the wood and rope overboard, allowing the wood to float behind the ship while counting the number of knots that passed through their hands in a certain amount of time. This method of measuring speed was known as "dead reckoning", and over time, the term "knot" became associated with it.

Today, there are more modern methods of measuring a boat's speed, such as using a GPS unit or a speedometer. However, the knot remains the standard unit for measuring the speed of boats, and it is an important aspect of boating that every sailor should be aware of.

Storage

The first step is to measure the boat's length, width, and height, taking into account any protruding features such as antennas, trolling motors, or outboard engines. These measurements will help determine the required storage space and ensure the boat complies with maritime regulations. It is also important to measure the length of the trailer and trailer tongue if applicable.

There are three main types of boat storage units: indoor, outdoor, and covered. Indoor storage units offer the most protection from the elements and typically include security features and climate control options, but they may not accommodate larger boats. Outdoor parking is more affordable and suitable for boats of all sizes, but it provides less protection from the weather. Covered storage is a balance between the two, providing a roof but leaving the sides open.

When choosing a storage unit, it is essential to consider the size of the unit, including its shape, door width and height, and any obstructions that may impact manoeuvring the boat. It is also important to think about accessibility and additional amenities, such as electricity and climate control.

Frequently asked questions