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

  • Image of a 79 Gallon Trionic Marine Fresh Water Tank

    79 Gallon Trionic Marine Fresh Water Tank | WH-2079

    Introducing the 79 Gallon Trionic Marine Fresh Water Tank by One Clarion. This marine water tank is designed with a rectangular shape, making it easy to fit in various spaces. Its portable nature allows for convenient transportation and installation. The...

    $773.26
    Add to Cart
  • An image of a 75 Gallon Marine Holding Tank | BOAT61W

    80 Gallon Marine Fresh Water Tank | B458

    The 80 Gallon Marine Fresh Water Tank by One Clarion is the perfect solution for those who need a portable and above ground water storage option. This rectangular tank is made of polyethylene and comes in a natural white color. Measuring 62 1/4" in...

    $796.37
    Add to Cart
  • An image of a 60 Gallon RV Holding Tank | RV82H

    80 Gallon Marine Fresh Water Tank | B367

    Introducing the 80 Gallon Marine Fresh Water Tank by One Clarion. This rectangular tank is designed specifically for marine use, making it the perfect choice for boat owners and enthusiasts. With a portable design, this tank can be easily transported and...

    $995.21
    Add to Cart
  • An image of a 45 Gallon RV Holding Tank | RV87H

    80 Gallon Marine Fresh Water Tank | B363

    Introducing the 80 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine use, making it perfect for boats and other water vessels. With its rectangular shape, it can easily fit into tight spaces and...

    $631.67
    Add to Cart
  • An image of a 98 Gallon Marine Holding Tank | B530

    80 Gallon Marine Fresh Water Tank | B327

    Introducing the 80 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine use, making it perfect for boats and other water vessels. With its rectangular shape and above ground usability, it offers...

    $642.71
    Add to Cart
  • An image of a 58 Gallon RV Fresh Water Tank | RV42W

    80 Gallon Marine Fresh Water Tank | B299

    The 80 Gallon Marine Fresh Water Tank from One Clarion is a rectangular, portable tank designed for above ground use. Made from polyethylene in a natural white color, this tank measures 76" in length, 28" in width, and 10" in height. It is not designed...

    $642.71
    Add to Cart
  • An image of a 40 Gallon RV Fresh Water Tank | RVB456

    80 Gallon Marine Fresh Water Tank | B282

    Introducing the 80 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 80 gallons, providing ample...

    $796.37
    Add to Cart
  • An image of a 40 Gallon Marine Fresh Water Tank | B456

    80 Gallon Marine Fresh Water Tank | B260

    Introducing the 80 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine use, making it perfect for boats and other water vessels. With its rectangular shape, it can easily fit in tight spaces and maximize...

    $642.71
    Add to Cart
  • An image of a 19 Gallon RV Fresh Water Tank | RV27W

    80 Gallon Marine Fresh Water Tank | B230

    Introducing the 80 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine use, making it perfect for boats and other water vessels. With its rectangular shape, it can easily fit in tight spaces and maximize...

    $642.71
    Add to Cart
  • Image of a 80 Gallon Trionic Marine Fresh Water Tank

    80 Gallon Trionic Marine Fresh Water Tank | WH-2080

    The 80 Gallon Trionic Marine Fresh Water Tank from One Clarion is a rectangular, portable tank designed for above ground use. Made from polyethylene in a natural white color, this tank measures 30" in length, 27" in width, and 24" in height. It is not...

    $793.35
    Add to Cart
  • Image of a 80 Gallon Trionic Marine Fresh Water Tank

    80 Gallon Trionic Marine Fresh Water Tank | WH-2080-1

    Introducing the 80 Gallon Trionic Marine Fresh Water Tank by One Clarion. This marine water tank is designed with a rectangular shape, making it easy to fit in various spaces. Its portable nature allows for convenient transportation, while its above...

    $793.35
    Add to Cart
  • 80 Gallon Marine Water Tank MW-540. Technical drawing of a polyethylene water tank designed for marine vessels.

    80 Gallon Marine Water Tank MW-540

    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 80 Gallon Marine Water Tank, Part# MW-540, is engineered to meet the requirements of mobile...

    MSRP: $547.52
    $520.56
    Add to Cart