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 15 Gallon RV Fresh Water Tank | RV11W

    53 Gallon Marine Fresh Water Tank | B133

    Introducing the 53 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...

    $491.07
    Add to Cart
  • 53 Gallon Marine Water Tank MW-456. Technical drawing of a polyethylene water tank designed for marine vessels.

    53 Gallon Marine Water Tank MW-456

    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 53 Gallon Marine Water Tank, Part# MW-456, is engineered to meet the requirements of mobile...

    MSRP: $507.27
    $482.30
    Add to Cart
  • 53 Gallon Marine Water Tank MW-442. Technical drawing of a polyethylene water tank designed for marine vessels.

    53 Gallon Marine Water Tank MW-442

    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 53 Gallon Marine Water Tank, Part# MW-442, is engineered to meet the requirements of mobile...

    MSRP: $620.75
    $590.19
    Add to Cart
  • An image of a 45 Gallon Marine Holding Tank | B452

    54 Gallon Marine Fresh Water Tank | B472

    Introducing the 54 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine environments, making it perfect for your boating or fishing adventures. With a rectangular shape and a capacity of 54 gallons, this...

    $550.32
    Add to Cart
  • 54 Gallon Marine Water Tank MW-504. Technical drawing of a polyethylene water tank designed for marine vessels.

    54 Gallon Marine Water Tank MW-504

    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 54 Gallon Marine Water Tank, Part# MW-504, is engineered to meet the requirements of mobile...

    MSRP: $634.10
    $602.88
    Add to Cart
  • 54 Gallon Marine Water Tank MW-305. Technical drawing of a polyethylene water tank designed for marine vessels.

    54 Gallon Marine Water Tank MW-305

    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 54 Gallon Marine Water Tank, Part# MW-305, is engineered to meet the requirements of mobile...

    MSRP: $502.76
    $478.01
    Add to Cart
  • An image of a 60 Gallon RV Fresh Water Tank | RV54W

    55 Gallon Marine Fresh Water Tank | B528

    Introducing the 55 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine water storage. With its rectangular shape, it offers a space-efficient solution for your water storage needs. The tank is made from...

    $491.07
    Add to Cart
  • An image of a 50 Gallon RV Holding Tank | RV91H

    55 Gallon Marine Fresh Water Tank | B417

    Enhance your marine environment with the 55 Gallon Marine Fresh Water Tank from One Clarion. This rectangular tank is designed for above ground use and is portable for added convenience. Made from polyethylene in a natural white color, this tank is both...

    $667.82
    Add to Cart
  • An image of a 32 Gallon Marine Holding Tank | BOAT2W

    55 Gallon Marine Fresh Water Tank | B351

    Introducing the 55 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine water storage. Its rectangular shape allows for easy placement and efficient use of space. Made from durable polyethylene material,...

    $597.52
    Add to Cart
  • Image of a 55 Gallon Trionic Marine Fresh Water Tank

    55 Gallon Trionic Marine Fresh Water Tank | WH-2055-1

    Introducing the 55 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...

    $602.54
    Add to Cart
  • Image of a 55 Gallon Trionic Marine Fresh Water Tank

    55 Gallon Trionic Marine Fresh Water Tank | WH-2055

    Introducing the 55 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 space. Its portable nature allows for convenient transportation, while its above ground...

    $602.54
    Add to Cart
  • 55 Gallon Marine Water Tank MW-479. Technical drawing of a polyethylene water tank designed for marine vessels.

    55 Gallon Marine Water Tank MW-479

    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 55 Gallon Marine Water Tank, Part# MW-479, is engineered to meet the requirements of mobile...

    MSRP: $593.17
    $563.97
    Add to Cart