What are boats made of? (all materials explained for newbies)

Boats have been around ever since long back (1000s of years back) and played a crucial role in the human race. Boats typically float on water, so they need to be built well out of good materials to resist the water well. So, what are boats made of, and what materials do they use in boat construction (building) these days?

Today, most of the boats are made of 4 materials, i.e., Aluminum, Steel, Fiberglass, and Wood. Modern ships (big boats) are usually made of steel or aluminum or both, and small boats are made of fiberglass or wood or both. Still, some boats are made of other materials, but those 4 are used widely.

In the past, most of the boats in the world are made out of wood. But, today, most of the boats are usually made of aluminum, steel, fiberglass, and wood. People started using heavy metals like steel and lighter metals like aluminum as part of boat construction due to advancements in technology.

We will now see some of the material used in different types of boats, from a small boat made out of wood to big warships made out of heavy metals like steel to carry cumbersome (very heavy or hefty) equipment and even aircraft.

Boat Type	Material Used
Canoe	Wood, aluminum, molded plastic, fiberglass, or synthetic fiber composites.
Jon boat	Aluminum, wood, and fiberglass.
Fishing boats	Steel for smaller ones and fiberglass and wood for bigger ones.
Inflatable boat (dinghy)	Synthetic rubbers like PVC, polyurethane, etc.
Motor Yachts	Steel, aluminum, and composite fiber-reinforced plastic (sometimes).
Sailboats	Aluminum, fiberglass, wood, and steel.
Personal Watercrafts (Jet skis, WaveRunner, Sea-Doo)	Fiber-reinforced plastic (FRP) mostly.
Barges	Steel (nowadays) wood in the past.
Crises ships	Aluminum and high-strength steel.
Container ships	Steel, but other materials like aluminum, fiberglass are also used.
Tanker ships	Steel
Military/Navel ships	Specialized steel alloy

When I say ships are made of steel, it doesn’t mean that the entire ship from the bottom keel to the top is made out of steel. Generally, it means hulls are made of steel, and decks and others can be made from other materials. Still, the whole ship can be made out of steel, but the ship becomes heavier.

Generally, most of the large ships, warships, container ships, bulk carriers, etc., are made from high strength steel like specialized steel alloys and coated with anti-corrosion painting (aka bottom paint or anti-fouling paint). Medium and small-size boats are either made from steel, aluminum, wood, or fiberglass.

Smaller boats that are used by the majority of the people are made mostly from wood and fiberglass material. Aluminum is also used. But, steel isn’t that common in small boats since steel is heavier than aluminum, wood, and fiberglass; it becomes challenging for a small boat made of steel to perform well in waters.

Did you know? According to SCMO, there are almost 30 million recreational boats in the world; among them, approximately 18 million boats are owned by Americans for recreational use today. It clearly tells that most of the boats in the world are smaller ones.

We have traveled all the way from a small wooden boat carrying 100s of pounds in the past to making gigantic boats that can carry 100,000s of tonnes of weight, like building the biggest cruise ship in the world named Symphony of the Seas, which carries 100,000 of tones. See the video below, “the biggest cruise ship in the world.”

That being said, we will now explore the materials used in boat construction (building) “wood, steel, aluminum, and fiberglass” separately in a detailed way.

Related post – Check my article on What are boats used for? to know 9 of the common uses of boats (small and big boats included).

Are boats made of Wood?

Boats are traditionally made of wood in the past. Nowadays, fiberglass, steel, and aluminum are also used along with wood. However, many people are still constructing and using boats made of wood solely. Several wood types used in boat building are Teak, Oak, Mahogany, Cedar, Plywood, etc.

Timber means building material like wood. Timbers are large squared lengths of wood used for building a house or a boat.

Before looking into types of woods and their benefits and drawbacks, check this small video on how modern technology is being used to construct wooden boats, totally eliminating 100s of hours in making wooden boats in the past.

Types of wood used in boat construction (building)

The various types of wood used in boat construction (building) are Teak, Oak, Mahogany, Cedar, Plywood, Ash, Cypress, Pine, Larch, Elm, Fir, Iroko, etc. Most commonly, Teak, Oak, Mahogany, Cedar, and Plywood are used in boat construction (building) rather than rest.

Those 5 wood types are commonly used while building a boat out of wood due to their wide availability, durability, and advantages. That being said, we will now see some of the benefits and drawbacks of those woods quickly.

Related Post – How much does it cost to build a wooden boat? Check this article to know more about the total costs involved in building your own boat and its comparisons with pre-built ones.

1. Teak wood for boat construction (building)

Benefits of using teak wood in boat construction (building)

Teak wood is subjected to both stress and abuse, so it is moderately easy to bend the wood.
Teak wood is quite hard, dense, strong, and has natural chemicals that prevent rot.
Teak makes a deck insulated from direct sunlight, and, therefore, it makes the boat interiors (inside the boat) cooler.
With its closed-pore, oily texture, Teak is considered more water-resistant and overall more durable than mahogany.

Drawbacks of using teak wood in boat construction (building)

Teak wood is expensive, and it is not normally available in large sizes.
Teak wood is very hard compared to others; it is difficult to cut into different shapes.
Teak wood requires a lot of maintenance and care than other woods.
The moment you notice a loose bung or any in the deck, better fix it early; otherwise, it will become messier later on.

2. Oakwood for boat construction (building)

Benefits of using oak wood in boat construction (building)

Oakwood is solid wood with a straight grain (a pattern of fibers seen in a cut surface of the wood), serves well, and finishes well.
Oakwood is especially used in rounded hulls because of its amazing ability to be bent to the desired shape after being saturated with steam.
Oakwood is good for planking, frames, keels, and generally, where strong wood is necessary.
Oakwood is more durable due to the high natural content of tannic acid in it.

Drawbacks of using oak wood in boat construction (building)

Oakwood is prone to shrinkage, cracking, and swelling, so proper maintenance is often required.
Oakwood is heavy compared to other woods, making it hard to carry around and cut.
If you didn’t take proper care, the oakwood may shrink, which may turn into cracks.
Oakwood can easily be stained, and stain can darken and gives the unattractive two-toned look if not treated well in advance.

3. Mahogany wood for boat construction (building)

Benefits of using mahogany wood in boat construction (building)

Mahogany wood is often used in boat construction (building) due to its high-end durability, and it is naturally dense.
Mahogany wood is highly resistant to rot and decay naturally, making it a good choice for boats.
Mahogany wood is especially easy to work with, both with hand and machine tools.
Mahogany has the distinct advantage of broader availability, wider distribution, and more all-purpose use than others.

Drawbacks of using mahogany wood in boat construction (building)

Mahogany wood is heavy compared to other woods, making it hard to carry around and cut.
Mahogany wood absorbs sunlight; the wood’s color becomes darker over time if exposed to sunlight continuously.
Mahogany wood is more expensive due to its more durability.
Mahogany wood also requires a lot of maintenance compared to most of the woods.

4. Cedarwood for boat construction (building)

Benefits of using cedar wood in boat construction (building)

Cedarwood has natural chemicals that prevent rot, anti-insect, and anti-weed properties, so it is often used for planking.
Cedarwood has a tight grain, making it good for boat building and easy to work with.
Among all the three types of cedars (Red, Yellow, and Lebanon), Yellow cedar is the strongest and has exceptional resistance to rot as well.
Cedarwood is easy to work with.

Drawbacks of using cedar wood in boat construction (building)

Cedarwood also requires a lot of maintenance compared to most of the woods.
Cedarwood fades to a light greyish color over the years, which may not look good on boats down the line.
Cedarwood is expensive due to its high durability.
Cedarwood is more toxic than other woods.

5. Plywood for boat construction (building)

Benefits of using plywood in boat construction (building)

Plywood is the most common wood used for making small boats (DIY works).
Plywood is convenient and ubiquity for use.
Plywood provides a smooth surface for laminate or flat surface to stick on and can be polished or painted easily.
Plywood is less expensive and easy to cut in any shape compared to other woods like teak and mahogany.

Drawbacks of using plywood in boat construction (building)

Plywood will not last long, so it is definitely not something one would use for a bigger boat.
Plywood contains more voids (small empty spaces inside the wood).
Plywood is not durable since the voids trap moisture and accelerate rot and physically weaken the wood.
Plywood requires a lot of maintenance than any other woods used in boat construction (building).

6. Other woods used in boat construction (building)

Ashwood – Ashwood has fairly good rot resistance, and it bends well so that you can use this wood for rounded shapes well. The continuous exposure of ashwood to sunlight will definitely fade the wood’s natural color and make your boat look unattractive. And it also has an excellent strength to weight ratio.

Cypress wood – Cypress has its own chemical oil (cypressene), which gives it natural durability to rot and good for planking. Paint sticks well on the wood and lasts longer than many other kinds of wood. It also bends well and easy to work with this wood and can be used to make any round shaped designs.

Pinewood – Pinewood is another great wood for boat construction (building), especially for small boats. Pinewood bends well and can be used to make any round shaped designs. It is good wood and also has some rot resistance. Pinewoods are softwoods which work to bend and finish reasonably well.

To know more about wood types used in boat construction (building), check this link from the DIY boat wood website.

Check this small video on the wood selection process by Louis Sauzedde to know why the right wood selection is important for a boat than looking at the name and buying it.

Some of the drawbacks of using wood in boat construction (building)

Wooden boats often undergo many problems such as wood rot, shrinkage, cracking, and swelling; they won’t last long enough and requires a lot of maintenance costs. However, doing regular maintenance will immensely cut down most of the maintenance costs.

Regular maintenance is required for a wooden boat to help maintain and support the boat’s structure’s durability. Cracks, swells, and rot on the wood need to be repaired or replaced early to prevent further damages. These repairs can sometimes be costly and time-consuming.

For example, if you keep a wooden boat and fiberglass, steel, or aluminum boat in the water for the same periods of time (say 2 weeks), you can see growth (slime, algae, etc.) on both the hulls for sure. The key differentiating thing is a fiberglass boat can be cleaned easily and quickly compared to a wooden boat.

And removing barnacles off the boat’s hull isn’t a big deal on a fiberglass, steel, or aluminum boat compared to a wooden boat because while scrubbing the hull of a wooden boat, you need to be very careful; otherwise, applying more power may result in peeling off the wood (however, wood won’t get peeled out that easily).

Wood is soft and not solid enough compared to steel or aluminum, so metals last longer than wood. But, any material requires maintenance down the line; even not taking proper care of boats made out of materials other than wood can result in damage down the line.

Are boats made of metals (steel and Aluminum)?

Steel and aluminum are common metals used in the construction (building) of most moderns ships (big boats). Since steel weighs more, aluminum is becoming more popular these days. Even small boats such as fishing boats, Jon boats, etc., are mostly built using aluminum as a material.

Other than steel and aluminum, there aren’t any alternative metals that are popular in boat construction (building). Aluminum and steel are the very opposite metals in terms of cost and weight. Aluminum weighs less and expensive, whereas steel weighs more and inexpensive.

That being said, we will now see about those two metals in a detailed way.

Check this small and quick video on a big Cruise ship (biggest ones) construction from scratch to the end to know how tons of metal is carried and shaping them into a gigantic boat.

Are boats made of Steel?

Most of the large ships, warships, container ships, bulk carriers, etc., are made of steel these days and coated with anti-corrosion painting (aka bottom paint or anti-fouling paint). Small and medium-sized ships are either made from steel, aluminum, wood, or fiberglass, but steel is not common.

Steel has carbon content in it, making it harder, more dent resistant, and more durable when stressed. Steel is strong and less likely to warp, deform or bend underweight, force or heat. So, that is the main reason why warships and big container ships, etc., are made of steel.

Boats are also made out of stainless steel, and don’t think that steel and stainless steel are the same. Stainless steel is normal steel with a distinguished amount of chromium added to it (at a minimum, more than 10% chromium). Chromium is a hard and brittle transition metal.

A well-maintained hull made out of steel with a good coating system can last almost indefinitely, as long as it’s kept properly painted and rust-free. It’s not uncommon to see steel boats using for 50 or 60 years still in service if they’ve been kept in good condition and regularly repainted.

If you want something built in your own special way, steel allows that at a moderate cost. It is also completely recyclable at the end of its life cycle and hence is a sustainable material for boats. That being said, we will now see some of the key benefits and drawbacks of using steel in boat construction (building).

Benefits of using steel in boat construction (building)

Steel is inexpensive (less expensive) compared to other metals like aluminum. Although when you add in the blasting, painting, and insulation costs, a steel vessel with a ‘yacht finish’ and long life expectancy will cost far more than a production fiberglass (GRP) boat.
Steel boats last longer than the boat made of other materials like fiberglass, wood, etc. It’s not uncommon to see steel boats using for 50 or 60 years still in service if they’ve been kept in good condition and regularly repainted.
Steel boats are durable (strong) than the boat made of other materials like fiberglass, wood, aluminum, etc. Steel’s carbon content makes it harder, more dent resistant, and more durable when stressed. Steel is strong and less likely to warp, deform or bend underweight, force or heat.

Drawbacks of using steel in boat construction (building)

Steel boats are heavier than the boat made of other materials like fiberglass, wood, aluminum, etc. So, a boat made out of steel covers less distance than the same sized aluminum boat and consumes more fuel since a boat displaces more space in the water if it’s heavy and it needs to push more water out of its way, increasing fuel consumption. Steel is 70% heavier than aluminum.
Steel boats are more corrosive than the boat made of other materials like fiberglass and aluminum. Steel, in contrast, reacts with oxygen from water to form a relatively unstable iron oxide/hydroxide film (rust) that continues to grow with time and exposure to water and air.
Steel boats need more maintenance than the boat made of other materials like fiberglass and aluminum. Steel boats always need repainting and never look as good as a fiberglass boat. Due to its corrosive nature, it often requires repainting.

Are boats made of Aluminum?

The boats that seek performance, such as racing boats, cigarette boats, planning hull boats, fishing boats like bass boats, Jon boats, etc., are made of aluminum. Due to its lightweight nature, the boat weighs less than a steel boat and others, increasing the speed, and decreases fuel consumption.

Aluminum is a very common material in boat construction (building), but comparing that with steel isn’t a good choice because both have their own advantages and demerits; it depends on the boater’s needs. But, steel is a solid and strong material compared to aluminum.

For example, a racing boat built for speed makes aluminum the better choice because of the weight saving and performance increase; an explorer yacht or ship, on the other hand, will require a hull that is much more durable, and that is where steel’s abrasive resistance will be needed.

Benefits of using aluminum in boat construction (building)

The aluminum boat weighs less than the boat made of other materials like fiberglass and steel. A decrease in weight increases the vessel’s performance and speed, decreasing fuel consumption since it displaces less water, and no need to push more water out of its way.
Aluminum is more corrosion resistive than a boat made of other materials like steel. The corrosion resistance of aluminum is due to its tendency to form a compact oxide layer over the surface. The oxide formed offers high resistance to corrosion (however, seawater can be dangerous).
Aluminum is malleable, meaning more elastic in nature than steel. Aluminum can go places and create shapes that steel cannot, often forming deeper or more intricate spinnings. Especially for parts with deep and straight walls, aluminum is a good material of choice.

Drawbacks of using aluminum in boat construction (building)

Aluminum is expensive than other materials like steel, fiberglass, and wood. Tonne for tonne, the cost of aluminum is much greater than steel. When this article is written, aluminum’s cost per tonne is 1,945 dollars, whereas steel’s cost per tonne is 700 dollars, which is 3 times expensive than steel.
Aluminum is less abrasive than other materials like steel. Aluminum is a softer metal and malleable than steel, so aluminum is more susceptible to abrasion. So, proper maintenance is often required to overcome any damages.
The aluminum boat requires more maintenance than the boat made of other materials like steel. Small dents in aluminum hulls can be fixed easily and quickly than in steel boats; however, it is difficult and costly to repair when larger damage occurs on an aluminum boat.

Are boats made of Fiberglass?

Small boats like jetboats, bay boats, center console boats, deck boats, cabin cruisers, etc., are usually made of fiberglass. But, ships (big boats) are usually made of metals like steel or aluminum since they have to handle more weights and overcome harder environments than small boats.

Fiberglass had greater advantages over wood when it was first introduced in terms of cost and durability. For example, a wooden boat’s construction and building take 10,000 dollars, whereas the same boat with fiberglass would take anywhere between 3,000 dollars to 5,000 dollars, which is cheaper.

Fiberglass is stronger than wood and does not need to be caulked to be waterproof when the proper gel coat is applied. Since fiberglass is stronger than wood, the boats’ hulls can be made thinner and the inside area larger. This is very good from the view of someone looking to buy a boat for recreational purposes.

Benefits of using fiberglass in boat construction (building)

A fiberglass boat is more corrosion resistant in nature than a boat made of other materials like steel. Since there is no metal anywhere on the hull exposed to the water, corrosion doesn’t happen on a boat made of fiberglass (but marine growth is common).
Fiberglass boats are easy to maintain than a boat made of other materials like steel. Since corrosion isn’t a problem on a fiberglass boat, it reduces half of the maintenance works and costs; the only maintenance is required for growth on the hull.
Fiberglass is more malleable than a boat made of other materials like aluminum, wood, and steel. Manufacturers may make an entire boat frame out of 1 or 2 parts by molding fiberglass in the mold, while steel or aluminum, or wood would take thousands of parts. This alone makes fiberglass ideal for the production line.

Drawbacks of using fiberglass in boat construction (building)

Fiberglass boats cause blistering (osmosis) when the water passes through the gel coat and forms a dome-like structure under the gel coat due to some chemical reaction between the water and under the gel coat. It will destroy the look of the boat and damages the hull’s paint (if any).
Fiberglass boats weigh more than a boat made of wood. However, a fiberglass boat can’t be heavier than a boat made of steel, but there are stronger than a boat made of steel.

Other materials used in boat construction (mostly very small boats)

Fiber reinforcement plastic (FRP) is used in personal watercraft (Jetski, Sea-Doo, and WaveRunner) construction.
Molded polyethylene (plastic) is used in a kayak and sometimes in canoe construction as well.
PVC and rubber are used in inflatable ribs construction. If it is just a dinghy, then only rubber is used.

Those are some of the materials used in boat construction other than steel, aluminum, fiberglass, and wood.

Key takeaways

Most of the boats are mostly made of steel, aluminum, fiberglass, and wood these days. Since metals are stronger than wood and fiberglass, they are mostly used in ships (big boats), whereas small boats are usually made of fiberglass. However, steel, aluminum, and wood are also used in the construction of small boats.

Generally, most of the large ships, warships, container ships, bulk carriers, etc., are made from high strength steel and coated with anti-corrosion painting (aka bottom paint or anti-fouling paint). Medium-size ships are either made from steel, wood, or fiberglass.