What are The Different Grades Of Marine Plywood?

There are different grades of marine plywood; available grades are A-A, A-B, B-B, MDO (Medium-density overlay), and HDO (High-density overlay). Plywood grades can vary depending on the country or region.

A-A Grade

A-A grade is also known as an exterior grade. It is considered the highest quality plywood as it uses A-grade veneer on both sides of the plywood. In which there are no knots and defects. This grade is used to make high quality applications.


A-A grade is used for boats, docks, siding, decks, and all applications exposed to extreme weather or moisture. 

A-A grade Marine Plywood Pros and Cons


  1. High Quality: Front and back side veneer are of A-grade (knots and defects free) quality, which is moisture and weather resistant. A-A grade is durable and stable as compared to other grades.
  2. Versatile Uses: A-A grade can be used for indoor or outdoor purposes.
  3. Required Less Maintenance: This grade requires the least care and maintenance compared to other grades.


  1. Very Expensive: A-A grade marine plywood is the most expensive grade among all the grades. Because A -A grade is made from the highest quality veneer and waterproof glue.

A-B Grade 

A-B grade is high-quality plywood, A-grade veneer is used for the front side, and B-grade veneer is used for the back. Few knots and defects may be present in B-grade veneer, but they are still of high quality and can withstand exposure to moisture.


A-B grade marine plywood is commonly used in boat building, subfloors, and exterior walls. It can be used for all applications with the front face open and the back face hidden inward.

A-B grade Marine Plywood Pros and Cons


  1. High quality: A-B grade plywood is considered high-quality because it is made from defects-free wood veneers.
  2. Durable: A-B grade plywood is durable and resistant to warping and cracking, making it a good choice for outdoor projects that require strength and stability.


  1. Expensive: A-B grade plywood is generally more costly than regular plywood because it is higher quality but cheaper than A-A grade.
  2. May require additional finishing: Front side of the plywood is smooth and attractive. The back side may require additional finishing if visible in the final product.

B-B Grade

B-B-grade marine plywood is moderately durable and stable. Both sides of B-B grade plywood are made with B-grade veneer. This grade has fewer knots and defects and can withstand moderate amounts of moisture and weather conditions.


B-B grade plywood is a good choice for applications where appearance is essential, such as furniture, cabinetry, and interior finishing. This grade is also used for subflooring and sheathing but is not considered a good option for external use.

B-B grade Marine Plywood Pros and Cons


  1. Easy to work with: B-B grade plywood is relatively easy to cut and shape, which makes it a popular choice for DIY projects.
  2. Versatility: Can be used in a wide range of applications, from furniture to subflooring.
  3. Cost-Effective: Compared to other grades of plywood, B-B grade plywood is relatively inexpensive, making it a cost-effective option for many applications.


  1. Not strong enough: B-B grade plywood may not have the same strength and durability as A-A and A-B grades, which may limit its use in some applications.
  2. Not suitable for exterior use: B-B grade plywood is not recommended for external applications, as it may not withstand exposure to moisture and weather conditions.
  3. Knots and defects may be present: Knots and defects may present on both sides of B-B-grade marine plywood due to B-grade veneers.

MDO (Medium-Density Overlay)

MDO panels are known for their durability, stability, and resistance to moisture and weather. C-grade and B-grade veneers are used to make MDO plywood. Each veneer is glued perpendicular to each other with waterproof glue to provide stability under high pressure and temperature.

MDO plywood is available in various thicknesses and sizes and can be custom cut to meet specific project requirements.


MDO is a versatile plywood used for siding, flooring, roofing panels, and other outdoor applications such as signboards, billboards, and highway sound barriers. This grade can be used for all applications that require a smooth, uniform surface.

MDO-Grade Marine Plywood Pros and Cons


  1. Durability: MDO-grade marine plywood is highly durable and can withstand humidity and extreme temperatures.
  2. Water resistance: It is highly water-resistant and essential in marine environments.
  3. Smooth surface: MDO-grade has a smooth surface, making it ideal for applications requiring a clean and uniform finish.


  1. Cost: MDO-grade marine plywood is more expensive than standard plywood due to its higher quality and added features.
  2. Weight: MDO-grade marine plywood is heavier than other types of plywood, So there may be trouble in working.
  3. Limited availability: MDO-grade marine plywood is not widely available, making it challenging to source for specific projects.
  4. Hard to work: The overlay layer on MDO-grade marine plywood can make it difficult to cut and shape, requiring specialized tools and equipment.

HDO (High-Density Overlay)

HDO marine grade plywood is extremely strong, durable, rot, and weather resistant, specially designed for marine environments. This grade is made with a thermosetting resin-impregnated fiber on both plywood sides under heat and pressure.


HDO marine-grade plywood is used on boats, docks, and other marine structures constantly exposed to moisture and weather conditions.

HDO grade Marine Plywood Pros and Cons


  1. Warping Resistant: HDO marine-grade plywood is highly resistant to warping and cracking.
  2. Smooth Surface: The surface of HDO marine plywood is smooth and hard, so it does not absorb moisture, making it ideal for industrial and commercial applications.


  1. Very Expensive: HDO marine grade plywood is the costliest grade compared to other grades, as it is made from the highest quality material.
  2. Weight: HDO marine plywood is heavier than other types of plywood. Being high-density and heavier also makes it difficult to work.

Marine Plywood Price

Marine-grade plywood is usually twice as expensive as ordinary plywood due to its high quality. Generally, marine-grade plywood can cost anywhere from $40 to over $100 per sheet. The cost of marine-grade plywood can depend on the size, thickness, and grade of the plywood, as well as the location and availability of the product.

Is Marine Plywood Good For Boats?

Yes, marine-grade plywood is suitable for boat making because it performs better in moisture or water than other wooden materials. Marine-grade plywood remains durable even when exposed to constant moisture or water.

What is Marine Treated Plywood?

Common or ordinary marine plywood that has been pressure-treated with chemicals is called Marine Treated Plywood. 

Treated marine-grade plywood is more resistant to rot, mold, and moisture than regular plywood. Treated plywood is designed to withstand exposure to moisture and weather. This treated marine plywood cost more than untreated plywood.

What is Sapele Marine Plywood?

Marine plywood is made from a variety of wood species. The properties and usefulness of plywood depend on the species of wood. Sapele Marine Plywood is made from Sapele species wood; hence it is called Sapele Marine Plywood.

Sapele Marine Plywood is highly durable and stable for furniture, boat furnishings, and decoration. The color of Sapele Marine Plywood is reddish brown.

What is Birch Marine Plywood?

Birch marine plywood is a high-quality plywood made from birch veneers, known for its strength and durability. This type of plywood is often used in marine and other outdoor applications where resistance to water and moisture is essential.

Read Also

How to identify marine plywood?