Marine Water Tanks

Custom Fitted for No Leaks!

white mrine fresh water tank with orange capsExplore our collection of top-tier marine fresh water tanks, meticulously crafted using FDA-approved virgin polyethylene plastic resins, all at prices that can't be beat! These tanks are engineered to deliver unparalleled quality and performance across a wide range of marine applications. Whether you need boat water tanks, graywater tanks, marine fresh water tanks, water storage tanks, ballast tanks, or any other water-related solution, our seamless, one-piece construction guarantees water purity and eliminates the risk of leakage or contamination.

We take immense pride in tailoring robust and long-lasting marine tanks to your precise specifications, ensuring a flawless and leakproof fit for your marine needs. Specifically designed for potable water storage, our marine fresh water tanks comply with FDA regulation CFR 177.1520 and Coast Guard Standards. Enclosed entirely, these poly water storage tanks feature walls that are a formidable 3/8" thick, providing exceptional strength and ensuring a prolonged service life.

Should you require a tank of a unique size or shape, our knowledgeable team members are ready to assist you every step of the way. We are committed to helping you acquire the ideal tank that perfectly aligns with your specific project requirements. Reach out to us today and discover the difference of our premium marine fresh water tanks.

For more detailed information, please refer to our Marine Water Tanks (pdf)


Custom Marine Water Storage Tanks

Enjoy the exceptional quality of our marine fresh water tanks, skillfully crafted using FDA-approved, virgin polyethylene plastic resin. Designed specifically for storing potable water in various marine vessels such as sailboats, yachts, and deep-sea fishing boats, these tanks offer the perfect blend of durability and practicality. With their seamless, one-piece construction, you can rely on these marine tanks to provide a dependable water storage solution. Bid farewell to concerns about cracks or weakening over time, as our plastic marine tanks are built to withstand the demanding conditions of marine environments.

To enhance convenience, these tanks are equipped with strategically positioned female NPT openings on one end, ensuring compatibility with marine plumbing systems. This thoughtful design facilitates seamless integration and simplifies installation. The inclusion of spin welded fittings guarantees protection against leaks and provides a secure fit.

At One Clarion, we take pride in delivering the highest quality marine tanks available on the market. Trust us to provide you with a reliable solution for your marine water storage needs.

Marine Tanks
Bow Shaped Water Tanks

dump waste tank drawing
Part No. Capacity Length Width Depth Drawings
W-367 8 19.5 13.5 7.5 drawing (pdf)
W-370 12 24 15 10 drawing (pdf)
W-415 13 22 19.5 14.75 drawing (pdf)
W-366 15 36 13.5 7.5 drawing (pdf)
W-361 16 15 25.25 13 drawing (pdf)
W-446 18 41 25.5 16 ask for details
W-428 20 23 16.5 15.5 ask for details
W-449 20 34.5 21.1875 11.75 ask for details
W-413 21 34 15 10.75 drawing (pdf)
W-414 22 24 21.25 15.25 drawing (pdf)
W-460 23 21.5 34.5 12 ask for details
W-365 25 59 13.5 7.5 drawing (pdf)
W-421 30 31 18 16 drawing (pdf)
W-464 34 31 30 12 drawing (pdf)
W-412 35 34 29.5 9 drawing (pdf)
W-363 35 66 15.5 9.75 drawing (pdf)
W-359 56 90 17.5 12 drawing (pdf)
W-360 56 90 17.5 12 drawing (pdf)

Rectangle Shaped Marine Water Tanks

rectangular shape tank
Part No. Capacity Length Width Depth Drawings
W-364 2 gallons 9.75 9.75 6 drawing (pdf)
W-49 3 gallons 16 7.5 6.5 drawing (pdf)
W-77 5 gallons 15.5 15.5 5 drawing (pdf)
W-369 6 gallons 16 12 8 ask for details
W-354 6 gallons 17 12 8 drawing (pdf)
W-26 8 gallons 19.25 13 9.5 drawing (pdf)
W-306 8 gallons 36 16 4 ask for details
W-376 8 gallons 54 6 7 ask for details
W-245 9 gallons 17.625 15.625 8.25 ask for details
L-1 10 gallons 18 16 8 drawing (pdf)
W-53 10 gallons 24 14.5 7.5 drawing (pdf)
W-210 10 gallons 24 15.5 8 drawing (pdf)
W-33 10 gallons 31 15.5 6 drawing (pdf)
W-294 10 gallons 40 25 9.25 drawing (pdf)
L-2 12 gallons 24 16 8 drawing (pdf)
W-28 13 gallons 30 14 8.25 drawing (pdf)
W-355 15 gallons 17.75 14.75 14.75 drawing (pdf)
W-27 15 gallons 22.25 13 13 drawing (pdf)
W-327 15 gallons 23 16 11 drawing (pdf)
L-3 15 gallons 30 16 8 drawing (pdf)
W-97 15 gallons 33 21.5 5.75 ask for details
W-328 15 gallons 48.5 10.75 7.875 drawing (pdf)
W-282 16 gallons 30.125 17.25 8 drawing (pdf)
W-209 19 gallons 36 15.5 8 drawing (pdf)
W-51 20 gallons 21 17 14 drawing (pdf)
W-80 20 gallons 24 17.75 12 drawing (pdf)
W-368 20 gallons 24.5 15.5 13.5 drawing (pdf)
W-95 20 gallons 30 18 9 drawing (pdf)
W-81 20 gallons 33.25 17.25 8.75 drawing (pdf)
L-4 20 gallons 36 16 8 drawing (pdf)
W-320 21 gallons 21 21 12.5 drawing (pdf)
W-371 21 gallons 29 20 9 drawing (pdf)
W-268 22 gallons 35 14 12 ask for details
W-304 25 gallons 25 21 12 drawing (pdf)
W-45 25 gallons 27 20 12 drawing (pdf)
W-85 25 gallons 34 17.5 11 drawing (pdf)
W-20 25 gallons 42 16 10 ask for details
L-5 25 gallons 48 16 8 drawing (pdf)
W-201 25 gallons 52.5 12 10.75 drawing (pdf)
W-31 27 gallons 21 18 18 drawing (pdf)
W-2 27 gallons 35 15 13 drawing (pdf)
W-335 27 gallons 42.5 17.5 9 drawing (pdf)
W-285 27 gallons 44 17 9 drawing (pdf)
W-225 28 gallons 34.25 17.5 12 ask for details
W-207 28 gallons 35.25 15 13 drawing (pdf)
W-55 28 gallons 52 12 11 drawing (pdf)
W-323 29 gallons 25 24 12 drawing (pdf)
W-244 30 gallons 29.75 25.75 9.5 drawing (pdf)
W-30 30 gallons 32 20 12 drawing (pdf)
W-254 30 gallons 33 20 11 drawing (pdf)
W-292 30 gallons 34.5 18 12 drawing (pdf)
W-233 30 gallons 35.5 19 10.75 drawing (pdf)
W-32 30 gallons 42 28 6.5 drawing (pdf)
W-280 30 gallons 44 14 12 drawing (pdf)
W-338 30 gallons 45.5 22 7.75 drawing (pdf)
W-236 32 gallons 50.5 20 8 ask for details)
W-373 32 gallons 64 24 5.25 drawing (pdf)
W-237 33 gallons 30 16 16 drawing (pdf)
W-332 33 gallons 42 21.5 9 drawing (pdf)
W-234 34 gallons 48 21 8 drawing (pdf)
W-22 35 gallons 31.5 19.5 14.75 drawing (pdf)
W-316 35 gallons 33 28 9 ask for details
W-202 35 gallons 37 20 12 drawing (pdf)
W-75 35 gallons 69 11 11 drawing (pdf)
W-324 38 gallons 41.5 17.75 12.5 ask for details
W-266 38 gallons 47 17 12.125 ask for details
W-3 38 gallons 48.5 14 13 drawing (pdf)
W-205 38 gallons 58.5 16.125 10 drawing (pdf)
W-227 38 gallons 71.5 13 10 drawing (pdf)
W-259 39 gallons 28.375 18 17.5 drawing (pdf)
W-257 39 gallons 55 28 6.25 drawing (pdf)
W-248 40 gallons 31 26 11.75 drawing (pdf)
W-291 40 gallons 31.75 28 11.25 drawing (pdf)
W-307 40 gallons 33 22.5 13.5 ask for details
W-293 40 gallons 34 16 17 drawing (pdf)
W-313 40 gallons 38 25 11 ask for details
W-17 40 gallons 41 15.25 15.5 ask for details
W-284 40 gallons 41 21 11 drawing (pdf)
W-296 40 gallons 41 21 11 drawing (pdf)
W-204 40 gallons 42.25 27 9.5 drawing (pdf)
W-96 40 gallons 54 20 9 ask for details
W-295 40 gallons 54 23.5 8 drawing (pdf)
W-1 40 gallons 58 14 12 drawing (pdf)
W-226 40 gallons 58 21 8 ask for details
W-270 40 gallons 60 18 9.375 drawing (pdf)
W-314 40 gallons 60 18 9.375 ask for details
W-231 41 gallons 50 19 10 drawing (pdf)
W-48 41 gallons 60 28 6 drawing (pdf)
W-380 43 gallons 99 13.75 7.5 ask for details
W-250 44 gallons 38 17 16 drawing (pdf)
W-38 44 gallons 42 26.5 9.5 ask for details
W-309 44 gallons 60 31 5.75 ask for details
W-24 45 gallons 40 19 16 drawing (pdf)
W-35 45 gallons 42 20 13 ask for details
W-25 45 gallons 48 28 8 drawing (pdf)
W-264 45 gallons 64 24 7.5 drawing (pdf)
W-79 47 gallons 48 19.75 12 drawing (pdf)
W-279 48 gallons 72 20 8 drawing (pdf)
W-249 50 gallons 26 21.5 21 drawing (pdf)
W-275 50 gallons 45 26 10 ask for details
W-289 50 gallons 48 18 14.5 drawing (pdf)
W-318 50 gallons 51 28 8.375 ask for details
W-330 50 gallons 54.75 27 8 drawing (pdf)
W-208 50 gallons 57 36 6 drawing (pdf)
W-228 50 gallons 64 32 6 drawing (pdf)
W-271 50 gallons 68 13.5 13.5 drawing (pdf)
W-212 52 gallons 58 24 9 drawing (pdf)
W-12 53 gallons 30.25 24.5 17.25 ask for details
W-305 54 gallons 55 28 8.375 drawing (pdf)
W-403 55 gallons 45 23 12.75 ask for details
W-302 55 gallons 51 21 13 drawing (pdf)
W-4 55 gallons 60 20.5 11 drawing (pdf)
W-76 57 gallons 48 24 12 drawing (pdf)
W-300 60 gallons 48 21.5 14.5 drawing (pdf)
W-74 60 gallons 50 18 16 drawing (pdf)
W-276 60 gallons 53.5 21 13 drawing (pdf)
W-277 60 gallons 57 28 9 drawing (pdf)
W-37 60 gallons 70 26 8 ask for details
W-59 60 gallons 79.25 15.75 11.5 drawing (pdf)
W-331 62 gallons 50 32 9 drawing (pdf)
W-223 65 gallons 34 24 18.5 ask for details
W-362 65 gallons 39.75 23.75 16.25 drawing (pdf)
W-241 65 gallons 60 22 11.5 drawing (pdf)
W-220 68 gallons 42.5 39 9.5 drawing (pdf)
W-84 68 gallons 48.5 26 13 drawing (pdf)
W-213 72 gallons 34.5 23 21.5 drawing (pdf)
W-34 74 gallons 65 20.75 13 drawing (pdf)
W-251 80 gallons 59 49.5 7 drawing (pdf)
W-315 93 gallons 71 27 11.5 ask for details
W-218 95 gallons 41 25.25 22 drawing (pdf)
W-230 97 gallons 67 48 7 drawing (pdf)
W-214 98 gallons 52 26 17 drawing (pdf)
W-221 100 gallons 36 27.5 23.5 drawing (pdf)
W-101 100 gallons 50 40 12 drawing (pdf)
W-68 103 gallons 59.25 23.625 17.75 ask for details
W-63 105 gallons 46.5 33 16 drawing (pdf)
W-88 105 gallons 48 24 21.5 drawing (pdf)
W-60 105 gallons 79.25 27 11.5 drawing (pdf)
W-310 105 gallons 92 27.5 10 ask for details
W-308 107 gallons 94 27 9.75 ask for details
W-238 128 gallons 64.5 40 11.5 ask for details
W-347 132 gallons 65 38 12.5 drawing (pdf)
W-239 140 gallons 64.5 43.5 11.5 drawing (pdf)
W-272 142 gallons 60 43 13.75 drawing (pdf)
W-108 145 gallons 50 31.25 22 drawing (pdf)
W-69 145 gallons 69.75 44 11 ask for details
W-56 160 gallons 64.75 43 13.75 drawing (pdf)
W-345 163 gallons 65 30.5 19.25 drawing (pdf)
W-372 188 gallons 62 40 17.5 drawing (pdf)

Marine Tanks
Wedge Shaped Water Tanks

l shaped side dump holding tank drawing
Part No. Capacity Length Width Depth Drawing
W-358 8 gallons 19.75 17.75 8 drawing (pdf)
W-375 17 gallons 24.5 22 9 drawing (pdf)
W-274 65 gallons 69 24.25 10.75 ask for details
W-273 70 gallons 73.75 24.25 10.75 ask for details
W-211 72 gallons 61.75 24 13 drawing (pdf)
W-281 81 gallons 70 26.75 11.75 drawing (pdf)
W-349 82 gallons 48 40.5 11 ask for details
W-224 88 gallons 73.75 24.25 12.75 ask for details
W-353 93 gallons 59 36.5 11.375 drawing (pdf)
W-303 97 gallons 73 24.75 14 drawing (pdf)
W-215 100 gallons 78 26 14 drawing (pdf)
W-99 105 gallons 60 40.5 11.5 ask for details
W-374 107 gallons 76 38.5 10.125 ask for details
W-350 108 gallons 76 40 10 ask for details
W-378 110 gallons 57 32 16 ask for details
W-93 150 gallons 67.5 40.5 14.25 drawing (pdf)



Simple Ordering Process

Our commitment to excellence drives us to provide the highest quality custom marine water tanks for your unique projects. Unlike pre-drilled tanks, these tanks offer a blank canvas, allowing you to precisely place holes and fittings exactly where you need them. This flexibility ensures that your custom boat water tank can pivot to fit seamlessly into your available space.

Here's how our streamlined ordering process works:

  1. Begin by completing a tank drawing, accurately depicting your tank dimensions and specifications. Clearly indicate on the drawing where you require the ports on your tank, providing precise measurements and locations. Submit the drawing to us using either the contact form or email, along with your specific requirements.

  2. Once our experienced team reviews your drawing, we will promptly reach out to you with valuable feedback and suggestions to optimize your tank design.

  3. We work closely with you, refining the design until you are completely satisfied. Once the design is finalized, we process your order efficiently and promptly.

  4. We encourage you to provide as much specific information as possible regarding your tank's size and location requirements. If you have any uncertainties or need guidance throughout the process, our dedicated team is readily available to assist you, ensuring necessary adjustments are made.

*Please note that mounting straps are not included with this tank, and it is not suitable for use with gasoline fuel storage. If you require a different type of tank, our team will gladly assist you in finding the perfect custom tank that precisely fits your specific needs.

Choose us for exceptional custom marine water tanks that are tailored to your project requirements!

Roto Molding for Marine Water Tanks

rotomolding process graphicMarine water tank manufacturing begins with the meticulous process of roto molding. High-quality virgin polyethylene resin is carefully heated and melted inside a sealed mold. This mold is then placed in a casting and heated to temperatures ranging from 260°C to 370°C. As the mold rotates, the molten resin uniformly coats its interior, ensuring the creation of smooth, strong walls with consistent thickness throughout. The result is a remarkably durable marine water tank that boasts exceptional strength and a seamless construction. Seamless is important in the tank world, as by having no seams, it eliminates weak points that are prone to cracking and leaking. With its robust design, these water tank offers longevity, providing you with a reliable and long-lasting solution for your marine water storage needs.



Marine Water Tank Accessories

At One Clarion, we take immense pride in our position as an industry leader, dedicated to meeting your specific requirements. We understand the importance of customization, which is why we offer tanks that can be tailored to fit your precise dimensions and specifications. To ensure a secure plumbing connection, we utilize spin weld fittings, guaranteeing a reliable and leak-free solution.

Should your project demand a unique size or shape beyond our existing offerings, we are more than capable of accommodating your needs. Our expertise extends to creating custom molds, allowing us to provide a truly bespoke solution for your specific requirements. Trust One Clarion to deliver exceptional quality and unmatched flexibility for your tank needs.

white fitting

Secure and Durable Connections with Spin Welding
To ensure the utmost strength and longevity of our holding tanks and fresh water tanks, we employ the reliable technique of spin welding. This straightforward yet effective process involves securely attaching polyethylene fittings to the tanks, resulting in a robust and long-lasting permanent joint connection. The use of spin welding not only creates a strong bond but also delivers a polished and seamless finish.

We offer the flexibility to customize fittings for your tanks, guaranteeing a precise fit that is both secure and watertight. Our fittings seamlessly integrate with your tanks, providing a reliable solution tailored to your specific needs. You can trust in the durability and dependability of our tanks, fortified by the exceptional quality of spin welding connections.

compartment drawing

Sturdy, Secure Storage:
In addition to our comprehensive range of products, we also offer a diverse selection of custom, watertight compartments designed to cater to your unique storage requirements. Our assortment includes rounded corner open-ended compartments, square corner open-ended compartments, as well as square corner top and end compartments, available in a variety of sizes. These meticulously crafted compartments are specifically designed to provide both convenience and versatility, guaranteeing efficient organization and storage solutions for your boat. Experience the ultimate in tailored storage with our custom compartments, ensuring your belongings are securely and neatly stowed away during your marine adventures.

For a comprehensive list of boat storage containers, please refer to our dedicated section.


battery box drawing

Battery Boxes
Protect your battery with our selection of battery boxes meticulously designed to deliver essential protection for your marine battery. Engineered with precision, these battery boxes are specifically crafted to safeguard against tipping, accidental short-circuits, and corrosion, ensuring optimal performance and prolonged battery life.

With our battery boxes, you can enjoy peace of mind, knowing that your marine battery is securely housed and shielded from potential hazards. Invest in the protection your battery deserves and embark on worry-free boating experiences. Trust our battery boxes to provide the reliability and security you need for your marine adventures.

  • Battery Box GRP-31-S
  • Double Battery Box End X End GRP-31-DE
  • Double Battery Box Side X Side GRP-31-DS
  • Optima Battery Box GRP-34-SO

Sustainable Custom Plastic Storage

 eco-friendly logo

These custom plastic marine tanks give a sustainable solution for environmental friendly water storage. Manufactured with non-toxic material, tanks have a low carbon emission during their life cycle. Our tanks can withstand corrosion, are leak proof, resist UV damage, and last longer than other tanks. Reduce your carbon footprint with these flexible, cost-effective plastic marine tanks.




Enjoy unparalleled customization options with this Marine Fresh Water Tank, tailored to meet your precise specifications for size, shape, and fit. Whether you require a water storage tank for your boat or any other marine tank, we specialize in creating the perfect solution to suit your project requirements.

To explore our extensive range of custom boat water tanks and other marine tanks, we invite you to speak with one of our knowledgeable team members. They will provide you with detailed information, guiding you through the process of selecting the ideal tank that perfectly aligns with your needs.

Don't settle for anything less than perfection when it comes to your marine water storage. Contact us today and let us assist you in finding the ideal custom solution for your boat water tank and other marine tank needs.

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