Marine Water Tanks

These NSF and FDA compliant marine water storage tanks are made to be incredibly strong, nearly unbreakable, and are very affordable. Plastic marine water tanks (poly) are available in nearly every size and shape. Made from one piece of thick poly, there are no seams so less opportunity for leaking, and made with a rotomold process for superior strength. You won’t find better-made marine fresh water tanks for the price. 

Made from one piece to form 3/8” thick walls using a roto-mold process to create a seamless holding tank superior in strength and performance. These custom fitted marine water tanks are built to go the distance.   

*Note: Customize the placement of the fittings when you place the order.  We spin-weld the fittings to ensure your holding tank is securely connected to your plumbing.

  • Complies with NSF 61, FDA Reg CFR 177.1520, and Coast Guard Standards
  • Made from virgin polyethylene (poly) resins
  • Seamless tank made from one piece (less likely to break or leak)
  • 3/8” thick tank walls
  • Customized fitting placement
  • Spin weld fittings
  • Outlasts the competition

For use as marine water tanks, marine fresh water tanks, plastic marine water tanks, poly marine water tanks, custom marine water tanks, and more!

We have 100’s of sizes ranging from 2 gallons, 40 gallons, 50 gallons, 100 gallon marine water tanks.  They range in size up to 250 gallons for these poly marine fresh water tanks.

Looking for something else? Chances are, we have it, and at affordable prices too!  Just call us and ask!

Pick the size and shape you need from the list. Mark up the drawing with your fittings placement. Call us with any questions!

Marine Water Tanks

  • An image of a 30 Gallon Marine Holding Tank | B418

    26 Gallon Marine Fresh Water Tank | B406

    Upgrade your marine vessel with the 26 Gallon Marine Fresh Water Tank from One Clarion. This rectangular tank is designed for portable use and is suitable for above ground environments. Made from polyethylene in a natural white color, this tank measures...

    $326.38
    Add to Cart
  • An image of a 32 Gallon Marine Holding Tank | B141

    26 Gallon Marine Fresh Water Tank | B338

    Introducing the 26 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is perfect for marine environments and is designed to be used above ground. With its rectangular shape, it offers a space-saving solution for storing fresh water on your...

    $362.53
    Add to Cart
  • An image of a 80 Gallon Marine Fresh Water Tank | B260

    26 Gallon Marine Fresh Water Tank | B332

    Upgrade your marine vessel with the 26 Gallon Marine Fresh Water Tank from One Clarion. This portable tank is designed for above ground use and is constructed with ANSI/NSF 61 approved resin, ensuring safe and reliable water storage. The rectangular...

    $362.53
    Add to Cart
  • An image of a 24 Gallon Marine Fresh Water Tank | B114

    26 Gallon Marine Fresh Water Tank | B329

    Introducing the 26 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is perfect for marine environments and is designed to be used above ground. With its rectangular shape, it offers a generous capacity of 26 gallons, providing ample...

    $386.63
    Add to Cart
  • An image of a 18 Gallon Marine Fresh Water Tank | B352

    26 Gallon Marine Fresh Water Tank | B145

    Introducing the 26 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is perfect for marine environments and is designed to be used above ground. With its rectangular shape and dimensions of 42" length x 19" width x 11 1/2" height, it...

    $362.53
    Add to Cart
  • 26 Gallon Marine Water Tank MW-466. Technical drawing of a polyethylene water tank designed for marine vessels.

    26 Gallon Marine Water Tank MW-466

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 26 Gallon Marine Water Tank, Part# MW-466, is engineered to meet the requirements of mobile...

    MSRP: $256.37
    $243.75
    Add to Cart
  • 26 Gallon Marine Water Tank MW-440. Technical drawing of a polyethylene water tank designed for marine vessels.

    26 Gallon Marine Water Tank MW-440

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 26 Gallon Marine Water Tank, Part# MW-440, is engineered to meet the requirements of mobile...

    MSRP: $334.55
    $318.07
    Add to Cart
  • 26 Gallon Marine Water Tank MW-201. Technical drawing of a polyethylene water tank designed for marine vessels.

    26 Gallon Marine Water Tank MW-201

    This tank ships in 6-8 weeks. Custom fitting placement is not available at this time. It can be ordered blank, or blank with a DIY Fitting Kit Custom Roto-Mold 26 Gallon Marine Water Tank, Part# MW-201, is engineered to meet the requirements of mobile...

    MSRP: $363.76
    $345.85
    Add to Cart
  • An image of a 125 Gallon Marine Fresh Water Tank | B243

    27 Gallon Marine Fresh Water Tank | BOAT24W

    Introducing the 27 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is perfect for marine environments and is designed to be used above ground. With its rectangular shape and dimensions of 43" length x 16" width x 10 1/2" height, it...

    $327.38
    Add to Cart
  • An image of a 10 Gallon RV Fresh Water Tank | RVB263

    27 Gallon Marine Fresh Water Tank | B459

    The 27 Gallon Marine Fresh Water Tank by One Clarion is the perfect solution for your portable marine water storage needs. With a rectangular tank shape and above ground usability, this tank is easy to transport and use wherever you need it. The tank is...

    $456.93
    Add to Cart
  • An image of a 58 Gallon Marine Holding Tank | BOAT63W

    27 Gallon Marine Fresh Water Tank | B420

    The 27 Gallon Marine Fresh Water Tank by One Clarion is a rectangular-shaped portable tank designed for above ground use. This tank is made of polyethylene material in natural white color and measures 37" in length, 25 1/2" in width, and 11" in height...

    $480.02
    Add to Cart
  • An image of a 27 Gallon Marine Fresh Water Tank | B459

    27 Gallon Marine Fresh Water Tank | B342

    The 27 Gallon Marine Fresh Water Tank by One Clarion is the perfect solution for your portable marine water storage needs. This rectangular tank is designed for above ground use and is made from high-quality polyethylene material in a natural white color...

    $386.63
    Add to Cart