Are you planning on buying a new boat?
Have you heard the term ‘draft’ and wondered what it meant?
Draft is one of the most important factors to consider if you want to buy a boat. The draft on a boat will determine how and where you can safely use your vessel.
Buying a boat is a big investment, and you want to be sure that the one you buy is suited to your needs, i.e. whether you can use it in deep or shallow waters.
Understanding a boat’s draft can help you make an informed decision, allowing you to buy the boat that truly makes you happy.
In this article, I will answer the question: what is draft on a boat? You will also find out why draft is important, tips on reading a boat’s draft, and how to choose between the different types of boat drafts depending on your needs.
So, without further ado, let’s jump right in!
Table of Contents
What is Draft on A Boat?
A lot goes into deciding which boat to buy. The condition, history, accessories, and aesthetics all play a role in the value and utility of the boat.
One of the most important decisions you will make when buying a boat is draft measurement.
So what is draft on a boat?
Draft is the vertical height between the waterline and the lowest point of the hull. It is how deep the hull can go, allowing the boat to float freely and without touching the bottom of the water body such as the sea, ocean, or lake.
The boat’s draft will tell you how deep the waters need to be to take your boat out safely. Before deciding on the best boat draft, you must determine where you want to use your boat in the first place.
If you plan to use your boat for offshore trolling where the waters are deeper, you will need a boat with a different draft than if you want to use your boat in shallow waters or near the shores.
Taking a boat with a shallow draft into deep waters is inconvenient and dangerous. The same is the case with a boat with a deep draft in shallow waters.
Boats are categorized into three main classes based on the type of hull. Draft on a boat is largely dependent on the full size.
Next, let’s look at the three hull categories.
3 Main Hull Styles
Boats fall under one of three different categories depending on their hull size. These categories include:
- Bay boats
- Offshore boats
Skiffs is an umbrella term used to describe small boats. Skiff boats share similar characteristics—they are small, open, and come with simple systems. They have a few seats, an outboard engine, and a shallow hull.
Due to their small size and simplicity, most skiffs are not suited for large, rough water bodies. If you want to take your boat out into shallow waters, a skiff boat with a draft of 3 to 4 inches may be suitable.
2. Bay Boats
Also known as flats boats, bay boats are suitable for getting to hard-to-reach areas in shallow waters.
These boats are typically larger than skiffs, and their hull is moulded into a V shape, making it a more powerful vessel for maneuvering shallow open waters.
Bay boats are, however, unsuitable for choppy waters. They should not be taken to deep seas or turbulent waters, given their smaller size and shallow hull.
Most bay or flatboats have a draft of 10 to 14 inches, allowing you to navigate shallow waters and slightly choppy conditions safely.
3. Offshore Boats
Offshore boats are much bigger vessels that allow you to get into the deep sea.
Navigating the deep seas in search of large fish requires a boat with a large hull that can stay afloat in these large and open water bodies.
Popular offshore boats include walk-around boats, center consoles, and sportfishing yachts. These boats have a deeper draft, usually 14 feet and above and are suitable for the immense depth of larger water bodies.
So, now that you know what draft is, you might be wondering why it is important. Let’s take a look at that next.
Why is Draft on A Boat Important?
Knowing the boat’s draft ensures that you use the vessel properly and safely. At a technical level, measuring a boat’s draft ensures that you safely balance the maximum load that the vessel can carry without compromising its stability.
When buying a boat, you certainly want one sizeable enough for you and your family and the occasional entourage of friends. If you use your boat for fishing, you also want to ensure that it can support the weight of the fish and the human passengers.
If you need a boat that can support significant weight, you should look for one with more draft to ensure balance, stability, and overall safety.
Placing excessive weight in a boat can push the hull further down toward the surface of the water body, increasing the chances of flooding in the chance that you encounter even the smallest waves.
Another danger of not considering a boat’s draft is that water can collect in the deck when the hull is too low. This water can freeze over the hull in cold weather or cooler waters, causing the engine to fail. The additional weight can also destabilize the boat.
International boat safety standards provide the minimum and maximum boat draft for different boats. When buying a boat, it helps to consider the typical weather patterns in the areas you plan to sail. Also, keep in mind that different water bodies in different regions have varying physical and chemical characteristics that should be accounted for when determining the most appropriate vessel to use.
Knowing the draft on a boat is a safety precaution. A shallow draft in deep waters lacks stability and can be thrown off by simple changes in weather or sea conditions. Drastic conditions can even cause the boat to flood, overturn, or capsize altogether.
How To Read Draft In a Boat?
Did you know that you can read a boat’s draft? Waterborne vessels have draft measures indicated on the sides close to the stern.
The draft measures are unmissable- they look like a large ruler with figures written on the boat. If you buy a large offshore boat, the draft markings will likely be on several locations for easier visibility. You can find the draft markings on the rear, front end, and in the middle of the boat’s hull in these vessels.
When buying a boat, you should also check the documentation; this usually includes information about the boat’s draft.
The method used to calculate the draft in a boat will vary from one boat to another. The draft is calculated from the gear below the boat for boats with inboard pod drives. This may include the propeller or rudder.
The draft measurements are indicated as the distance between the drive and water level for outboard boats. When the drive is up, the measurement is known as drive-up. When the drive is down, it’s known as drive down draft.
When the drive is up, the draft is measured from the bottom part of the boat or the keel. If the drive is facing down, the draft is measured from the skeg at the front of the propeller.
Some boats have their drive system located inside the vessel. The draft in these boats will be measured from the water surface to the keel.
It is important to remember that the draft measurements indicated in your vessel’s documents were taken when the boat’s fuel and water tanks were empty. These measurements also don’t include additional weight such as passengers or cargo.
Other factors such as the hull’s design and cargo and passengers’ weight distribution will influence the draft measurement.
To check your boat’s draft for accurate estimation, I recommend loading the amount of cargo and passengers the boat would normally carry.
Then, identify the boat’s lowest point, also known as the keel. Keep in mind that different vessels have different keels that will also be positioned differently. Take this into account when measuring draft on a boat as the position of the keel can increase the draft—the goal is to measure from the bottom part of your boat.
Next, measure the distance from the waterline where the boat’s side meets the water down to the lowest point of the boat. The draft of your boat is measured in centimetres or feet.
Which One is Better: Shallow Draft vs Deep Draft?
The choice between a shallow draft vs. a deep draft boat comes down to one question: How will you use your boat?
There are advantages and disadvantages to using either one of these two. Let’s talk about this in the next section.
Shallow Draft Boats
Many shallow draft boats do not have a keel and are flat at the bottom. The absence of the keen makes the boat less stable in deep or choppy waters.
This is one of the reasons shallow draft boats are best used in shallow and calm waters where a keel isn’t required.
Some boat owners opt to install an engine at the bottom of the vessel. This can be problematic when moving through shallow waters despite the boat having a shallow draft.
If you want to maneuver very shallow waters, your best bet is a shallow draft boat with a flat bottom.
Advantages of shallow draft boats
Here are some pros of using a boat with a shallow draft:
- The flat bottom in a shallow draft boat increases the vessel’s stability. This not only makes the boat safe but also comfortable to ride in shallow and sometimes rocky water bodies
- The flat hull lets you move through shallow waters without getting caught up in rocks or reeds
- These boats are generally smaller and easier to maneuver
Disadvantages of shallow draft boats
While shallow boat drafts have their advantages, they also have downsides. Here are the main disadvantages:
- Boats with a flat hull may be stable in shallow waters. But, these vessels can quickly lose their stability and dependability at the slightest change in conditions. Slight wind or small waves can easily throw the boat off balance.
- Shallow boats limit you to the very shallow waters. If you want to venture out near shore or even offshore, it would be neither safe nor possible to do it with a shallow boat with a flat hull and no keel.
Deep Draft Boats
Deep draft boats have a bigger, more pronounced hull that extends deeper into the water. In these vessels, the bottom of the hull is not always the lowest point.
Deep draft boats will typically come with a keel, which goes deeper into the water to increase the vessel’s stability. The addition of the keel gives these boats a deeper draft.
Like shallow draft boats, deep draft boats have advantages and disadvantages.
Advantages of deep draft boats
- Deep draft boats offer stability and reassurance when you are navigating choppy waters.
- If you are looking for a vessel that can safely navigate deep-sea water and survive the conditions there, a boat with a deep draft is the ideal choice.
Disadvantages of deep draft boats
The main disadvantages of a boat with a deep draft are:
- Deep dive boats don’t offer as much comfort, especially when riding in choppy waters.
- A deep draft boat may not be the best investment if you can only access shallow backcountry waters. These boats are best suited for larger water bodies such as lakes, oceans, and seas.
Summary: What is Draft on A Boat?
Draft is an essential factor when determining a boat’s suitability. Measuring the depth from the waterline down to the bottom-most part of the boat will give you a rough estimate of your vessel’s draft. Choosing a vessel with the appropriate draft for a particular use ensures safety and stability when using the boat.