How to Choose the Right Toilet Size for Your Boat?

For every boat owner, the bathroom on the boat is not big, but it is the key to comfortable sailing. However, when you are preparing to choose or replace the toilet for your boat, do you often feel confused? Faced with various sizes and models of marine toilets on the market, how should you choose to meet the use needs and comply with regulatory requirements?

Why Is the Size of Marine Toilets so Important? Not Just "It Works"

Choosing a marine toilet is not just a matter of measuring the size and stuffing it in. It directly affects several key areas:

• Space Use: Boat space is valuable. The wrong-sized toilet wastes space, making your bathroom feel cramped. It can also impact where other gear goes.
• User Comfort: A toilet that's too big or too small just isn't comfortable. The right size lets you sit properly, making your time on the water more enjoyable.
• Installation Ease: Picking the wrong size leads to installation headaches. You might need costly and time-consuming modifications, possibly even affecting the hull. Remember to consider where the waste outlet and water inlet are crucial.
• Regulatory Compliance: This is often overlooked but extremely important. Your toilet and its waste system must follow maritime rules. Ignoring these can lead to fines or even your boat being held.

Correct Steps and Key Indicators for Measuring Marine Toilet Dimensions

Before purchasing a new marine toilet, it is crucial to accurately measure the existing space. Please prepare a tape measure, paper and pen and follow the steps below:

• Available Depth: Measure from the farthest bathroom wall (or where you plan to put the toilet's back) to the front of the toilet. Leave plenty of legroom, ideally 15-20 inches (38-50 cm). Also, make sure the door can open without hitting the toilet.

• Available Width: Measure the widest point from side to side where the toilet will sit. Consider the space between the toilet's sides and any walls or cabinets. We recommend at least 15-18 inches (38-45 cm) from the toilet's centerline to a side wall or fixture. This ensures comfortable use.

• Available Height: Measure from the floor to the top of the toilet. Check for anything above it like a ceiling, window, or cabinet. Ideally, have at least 24-30 inches (60-75 cm) between the toilet and any overhead obstacle to prevent bumping after installation.
• Drain position and pit distance (center distance): This is one of the most critical measurements!
  • Floor or rear drain: Determine whether the drain of your boat is located on the floor (floor drain) or on the rear wall (rear drain).
  • Pit Distance: For floor drain toilets, measure the distance from the center of the drain to the rear wall. This dimension must match when buying a toilet. For rear drains, measure the height from the center of the drain to the floor.
• Water and power supply interface: Check the location of the existing water supply interface and (if you choose an electric toilet) the power supply interface to ensure that the new toilet can be easily connected.
• Hatch and passage: Don't forget to measure the width of the bathroom hatch and the passageway into the bathroom. Make sure that the toilet you buy can be smoothly carried into the installation location and that the door will not be blocked by the toilet when fully opened.

Tips: Measure several times and record the smallest dimensions to leave appropriate margins for installation and use. When measuring, you can even cut out the desired toilet's dimensions with cardboard and place it in the predetermined spot to simulate it, giving you a more intuitive feel for the actual space. Choosing the right size of the marine toilet is essential to maximize the use of cabin space and improve the comfort of use. The layout of different ships and the needs of passengers will affect the final choice. Want to understand different marine toilets and their systems before you choose one? Check out our ultimate guide to marine toilets.

Common Size Classification and Applicable Scenarios of Marine Toilets

Size is key when choosing a marine toilet. Toilets on the market broadly fall into three categories, each with applicable scenarios and dimensions (reference values below; always check product manuals for specifics):

Compact/small-size toilets

• Features: The smallest dimensions, with a depth of about 15.7-18.5", a width of about 13-15", and a height of about 11.8-15" (from the floor to the top of the seat). The seat is also relatively small, designed to save space to the extreme.
• Applicable to: Small sailboats, yachts, fishing boats, or any boats with extremely limited space.
• Advantages: Extreme space saving.
• Disadvantages: Comfort may be limited, not suitable for larger people.

Standard toilets:

• Features: Moderate dimensions, with a depth of about 17.7-21.6", a width of about 15-17.7", and a height of about 15-18.9" (from the floor to the top of the seat). The seat size is close to that of a home toilet.
• Applicable to: Medium-sized yachts and most leisure boats. It is the mainstream choice in the market, balancing space occupancy and comfort of use.
• Advantages: Good comfort and wide applicability.

Extra large/comfortable toilet:

• Features: Largest dimensions, depth of about 19.7-23.6+", width of about 17.7-21.6+", height of about 17.7-20.5+". Larger seat, providing the ultimate comfort experience.
• Applicable: Large luxury yachts, houseboats or ships with extremely high comfort requirements. Spacious bathroom space is required.
• Advantages: Provides comfort comparable to land homes.
• Disadvantages: Takes up a lot of space and is usually more expensive.

Regulatory Considerations: The Size of the Toilet Is Not the Bigger the Better

Here's how regulations influence your decision:

• Sewage Storage and Treatment:
  • Regulatory Requirements: Many areas, especially coastal waters and inland rivers, demand vessels have a sewage holding tank or a marine sewage treatment plant. These systems handle domestic wastewater before discharge.
  • Impact on Size: Both holding tanks and treatment plants need substantial space. Even if you pick a small toilet, the entire toilet-sewage system must fit within regulatory limits and your boat's available space. For portable toilets, consider their built-in tank capacity and the need for frequent shore-side emptying.
• Safety and Access:
  • Regulatory Requirements: Ship designs must prioritize crew and passenger safety. This includes clear passageways and emergency exits.
  • Impact on Size: An oversized toilet can obstruct the bathroom, block doors, or impede nearby passages. This violates safety rules. Selecting the right toilet size ensures ample space for safe movement.

Important Tip

Before choosing your toilet size, understand the waters you'll mainly navigate. Check the latest maritime regulations. Consult a professional about the required sewage tank capacity or treatment device for your boat. These "regulatory space" considerations are often more crucial than the toilet's physical dimensions itself.

Modiwell Portable Toilet: Space-Saving Comfort for Boats

• Easy to Carry and Store: This toilet has a smart, foldable design with collapsible legs. When folded, it's only 17¡åD x 17¡åW x 11¡åH. You can easily store it in a cabin corner or any small space.
• Comfortable Height: Unfolded, the seat stands at about 17¡å high. This comfortable height ensures adults have a pleasant experience onboard.
• Simple Regulatory Compliance: As a portable marine toilet, the Modiwell automatically seals waste in a dedicated garbage bag. It doesn't connect to your boat's fixed sewage system. This makes meeting regulations easier. Just empty it at a shore facility after docking.

With its unique folding design and comfortable height, the Modiwell portable boat toilet offers a practical and compliant solution for boats with limited space. It balances convenience with a good user experience.

Conclusion

Choosing the right size for a marine toilet is a big decision. It requires balancing space, comfort, functionality, and regulations. We hope this guide has helped clarify your thoughts, so you'll feel confident picking your toilet size. Remember, careful measurement and a full understanding of your sailing needs and relevant laws are key to making the best choice.