Building a custom swim platform
Building a custom swim platform

Discover how building a custom swim platform for your boat can enhance your boating experience, provide a safe space for swimmers, and save you money in the long run.

Building a Custom Swim Platform

Welcome to another exciting article in our DIY boat projects series! Today, we’ll be discussing how to build a custom swim platform for your boat. A swim platform is an essential addition to any boat, providing a safe and convenient space for swimmers to enter and exit the water, as well as a comfortable spot to relax and enjoy the sun.

In this comprehensive guide, we’ll cover everything you need to know about building a custom swim platform, from choosing the right materials and design to the actual construction process. So, grab your tools and let’s dive in!

Table of Contents

  1. Why Build a Custom Swim Platform?
  2. Choosing the Right Materials
  3. Designing Your Swim Platform
  4. Tools and Equipment
  5. Building the Swim Platform Frame
  6. Installing the Decking
  7. Adding Accessories and Finishing Touches
  8. Attaching the Swim Platform to Your Boat
  9. Maintenance and Care
  10. Conclusion

Why Build a Custom Swim Platform?

There are several reasons why you might want to build a custom swim platform for your boat:

  • Fit and Functionality: Store-bought swim platforms may not fit your boat’s specific dimensions or meet your unique needs. Building a custom platform allows you to create a space that is tailored to your boat and your family’s preferences.
  • Cost Savings: Purchasing a pre-made swim platform can be expensive, especially if you require a custom fit. Building your own platform can save you money and give you the satisfaction of a job well done.
  • Personalization: A custom swim platform allows you to add your own personal touches, such as unique colors, patterns, or accessories that reflect your family’s personality and style.

Choosing the Right Materials

When building a custom swim platform, it’s essential to choose materials that are durable, weather-resistant, and suitable for use in a marine environment. Some popular options include:

  • Marine-grade plywood: This type of plywood is specifically designed for use in marine applications and is treated to resist rot and decay. It’s a popular choice for swim platform construction due to its strength and affordability.
  • Composite decking: Composite materials, such as Trex or Azek, are made from a combination of wood fibers and plastic. They are highly resistant to rot, decay, and UV damage, making them an excellent choice for a swim platform. However, they can be more expensive than plywood.
  • Teak or other hardwoods: Teak is a popular choice for boat decking due to its natural resistance to rot, decay, and insects. Other hardwoods, such as mahogany or ipe, can also be used for swim platform construction. While these materials are beautiful and durable, they can be more expensive and require more maintenance than other options.

In addition to the primary decking material, you’ll also need to choose appropriate hardware, such as stainless steel screws and brackets, to ensure your swim platform remains secure and corrosion-free.

Designing Your Swim Platform

Before you begin building your custom swim platform, it’s essential to create a detailed plan and design. Consider the following factors when designing your platform:

  • Size and Shape: Measure your boat’s transom and determine the ideal size and shape for your swim platform. Keep in mind that a larger platform may provide more space for swimmers but could also add weight and drag to your boat.
  • Weight Capacity: Consider the weight capacity of your swim platform, especially if you plan to use it for activities such as diving or fishing. Ensure your chosen materials and construction methods can support the intended weight.
  • Accessories: Plan for any accessories you’d like to include on your swim platform, such as a boarding ladder, handrails, or storage compartments. Ensure your design accommodates these features and their required hardware.
  • Aesthetics: Consider the overall appearance of your swim platform and how it will complement your boat’s design. Choose materials and colors that match or enhance your boat’s existing style.

Tools and Equipment

Before you begin building your custom swim platform, gather the necessary tools and equipment. Some essential items include:

  • Tape measure
  • Circular saw or jigsaw
  • Drill and drill bits
  • Screwdriver
  • Sandpaper or orbital sander
  • Carpenter’s square
  • Level
  • Clamps
  • Safety goggles and gloves

Building the Swim Platform Frame

Once you’ve chosen your materials and designed your swim platform, it’s time to start building the frame. Follow these steps to construct a sturdy and durable frame:

  1. Cut the Frame Pieces: Using your design as a guide, cut the pieces for your swim platform frame from your chosen material. This will typically include several crossbeams and support brackets.
  2. Assemble the Frame: Lay out the frame pieces on a flat surface, ensuring they are square and level. Attach the crossbeams to the support brackets using stainless steel screws, making sure to pre-drill holes to prevent splitting.
  3. Reinforce the Frame: To increase the strength and stability of your swim platform frame, consider adding additional support brackets or diagonal braces at key stress points.

Installing the Decking

With your frame assembled, it’s time to install the decking material. Follow these steps to create a smooth and secure deck surface:

  1. Cut the Decking: Measure and cut your chosen decking material to fit the dimensions of your swim platform frame. Be sure to account for any overhang or edge trim you’d like to include in your design.
  2. Attach the Decking: Lay the decking pieces on top of the frame, ensuring they are evenly spaced and aligned. Attach the decking to the frame using stainless steel screws, pre-drilling holes to prevent splitting. Be sure to countersink the screws to create a smooth surface.
  3. Sand and Finish: Once the decking is securely attached, sand the entire surface to remove any rough edges or splinters. If desired, apply a finish or sealant to protect the decking material and enhance its appearance.

Adding Accessories and Finishing Touches

With your swim platform’s frame and decking complete, it’s time to add any desired accessories and finishing touches. Some popular options include:

  • Boarding Ladder: Install a folding or telescoping ladder to make it easy for swimmers to climb onto the platform from the water.
  • Handrails: Add stainless steel handrails around the perimeter of your swim platform to provide extra safety and support for swimmers.
  • Storage Compartments: Incorporate built-in storage compartments into your swim platform design to hold items such as life jackets, snorkeling gear, or fishing equipment.
  • Non-Slip Surface: Apply a non-slip surface treatment, such as marine-grade grip tape or rubber matting, to prevent slips and falls on your swim platform.

Attaching the Swim Platform to Your Boat

Once your custom swim platform is complete, it’s time to attach it to your boat. This process will vary depending on your boat’s design and the type of swim platform you’ve built. Some common attachment methods include:

  • Bolt-On: Attach the swim platform to your boat’s transom using stainless steel bolts and brackets. This method is secure and allows for easy removal if necessary.
  • Hinge System: Install a hinge system that allows your swim platform to fold up against your boat’s transom when not in use. This can be a space-saving option for smaller boats or those with limited storage.
  • Custom Mounting: In some cases, you may need to create a custom mounting solution to attach your swim platform to your boat. This could involve fabricating brackets or supports that are specifically designed for your boat’s transom and swim platform.

Maintenance and Care

To ensure your custom swim platform remains in excellent condition, it’s essential to perform regular maintenance and care. Some tips for maintaining your swim platform include:

  • Cleaning: Regularly clean your swim platform with mild soap and water to remove dirt, salt, and other debris. Avoid using harsh chemicals or abrasive cleaners that could damage the decking material.
  • Inspection: Periodically inspect your swim platform for signs of wear, damage, or corrosion. Address any issues promptly to prevent further deterioration.
  • Finishing: If you’ve applied a finish or sealant to your swim platform, be sure to reapply it as needed to maintain its appearance and protect the decking material.


Building a custom swim platform for your boat is a rewarding and practical DIY project that can enhance your boating experience and provide a safe and enjoyable space for your family to enjoy the water. By carefully selecting materials, designing a functional and attractive platform, and following proper construction techniques, you can create a durable and long-lasting swim platform that will serve you well for years to come.