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 160/205 Gallon Double Wall Tank | RONCO160205DC

    65 Gallon Marine Fresh Water Tank | B289

    Introducing the 65 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 65 gallons, allowing you to...

    $608.57
    Add to Cart
  • An image of a 42 Gallon RV Holding Tank | RV74H

    65 Gallon Marine Fresh Water Tank | B283

    Introducing the 65 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine use, making it perfect for boats and other watercraft. With its rectangular shape, it maximizes space efficiency while still...

    $549.32
    Add to Cart
  • An image of a 16 Gallon Marine Holding Tank | B399

    65 Gallon Marine Fresh Water Tank | B248

    The 65 Gallon Marine Fresh Water Tank offered by One Clarion is a versatile and portable solution for your marine water storage needs. With its rectangular shape and above ground usability, this tank is designed to fit seamlessly into your marine...

    $549.32
    Add to Cart
  • 65 Gallon Marine Water Tank MW-362. Technical drawing of a polyethylene water tank designed for marine vessels.

    65 Gallon Marine Water Tank MW-362

    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 65 Gallon Marine Water Tank, Part# MW-362, is engineered to meet the requirements of mobile...

    MSRP: $421.55
    $400.79
    Add to Cart
  • 65 Gallon Marine Water Tank MW-241. Technical drawing of a polyethylene water tank designed for marine vessels.

    65 Gallon Marine Water Tank MW-241

    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 65 Gallon Marine Water Tank, Part# MW-241, is engineered to meet the requirements of mobile...

    MSRP: $513.00
    $487.75
    Add to Cart
  • 65 Gallon Marine Water Tank MW-220. Technical drawing of a polyethylene water tank designed for marine vessels.

    65 Gallon Marine Water Tank MW-220

    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 65 Gallon Marine Water Tank, Part# MW-220, is engineered to meet the requirements of mobile...

    MSRP: $519.78
    $494.19
    Add to Cart
  • 66 Gallon Marine Water Tank MW-334. Technical drawing of a polyethylene water tank designed for marine vessels.

    66 Gallon Marine Water Tank MW-334

    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 66 Gallon Marine Water Tank, Part# MW-334, is engineered to meet the requirements of mobile...

    MSRP: $497.26
    $472.78
    Add to Cart
  • 67 Gallon Marine Water Tank MW-448. Technical drawing of a polyethylene water tank designed for marine vessels.

    67 Gallon Marine Water Tank MW-448

    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 67 Gallon Marine Water Tank, Part# MW-448, is engineered to meet the requirements of mobile...

    MSRP: $604.00
    $574.27
    Add to Cart
  • Image of a 68 Gallon Trionic Marine Fresh Water Tank

    68 Gallon Trionic Marine Fresh Water Tank | WH-2068-1

    Introducing the 68 Gallon Trionic Marine Fresh Water Tank by One Clarion. This marine water tank is designed with a rectangular shape, making it easy to fit into any boat or marine vessel. Its portable usability allows for convenient transportation and...

    $723.05
    Add to Cart
  • Image of a 68 Gallon Trionic Marine Fresh Water Tank

    68 Gallon Trionic Marine Fresh Water Tank | WH-2068

    Introducing the 68 Gallon Trionic Marine Fresh Water Tank by One Clarion. This portable marine water tank is designed in a rectangular shape, making it easy to fit in various spaces. With its above ground usability, this tank is perfect for boats and...

    $723.05
    Add to Cart
  • 68 Gallon Marine Water Tank MW-463. Technical drawing of a polyethylene water tank designed for marine vessels.

    68 Gallon Marine Water Tank MW-463

    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 68 Gallon Marine Water Tank, Part# MW-463, is engineered to meet the requirements of mobile...

    MSRP: $419.78
    $399.11
    Add to Cart
  • An image of a 65/90 Gallon Double Wall Tank | RONCO6590DC

    69 Gallon Marine Fresh Water Tank | B444

    Introducing the 69 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 offers a space-efficient solution for...

    $584.46
    Add to Cart