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

  • 50 Gallon Marine Water Tank MW-24. Technical drawing of a polyethylene water tank designed for marine vessels.

    50 Gallon Marine Water Tank MW-24

    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 50 Gallon Marine Water Tank, Part# MW-24, is engineered to meet the requirements of mobile...

    MSRP: $376.45
    $357.93
    Add to Cart
  • 50 Gallon Marine Water Tank MW-208. Technical drawing of a polyethylene water tank designed for marine vessels.

    50 Gallon Marine Water Tank MW-208

    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 50 Gallon Marine Water Tank, Part# MW-208, is engineered to meet the requirements of mobile...

    MSRP: $573.18
    $544.96
    Add to Cart
  • Image of a 51 Gallon Trionic Marine Fresh Water Tank

    51 Gallon Trionic Marine Fresh Water Tank | WH-2051

    Introducing the 51 Gallon Trionic Marine Fresh Water Tank by One Clarion. This portable marine water tank is designed with a rectangular shape, making it easy to fit in various spaces. With its above ground usability, this tank is perfect for boating and...

    $602.54
    Add to Cart
  • 51 Gallon Marine Water Tank MW-532. Technical drawing of a polyethylene water tank designed for marine vessels.

    51 Gallon Marine Water Tank MW-532

    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 51 Gallon Marine Water Tank, Part# MW-532, is engineered to meet the requirements of mobile...

    MSRP: $783.22
    $744.66
    Add to Cart
  • An image of a 42 Gallon Marine Holding Tank | B510

    52 Gallon Marine Fresh Water Tank | BOAT48W

    Introducing the 52 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine use, making it perfect for boating and other water activities. With its rectangular shape, it offers a space-efficient solution for...

    $456.93
    Add to Cart
  • An image of a 12 Gallon RV Fresh Water Tank | RVB105

    52 Gallon Marine Fresh Water Tank | B422

    Upgrade your marine vessel with the 52 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...

    $632.67
    Add to Cart
  • An image of a 7 Gallon Marine Fresh Water Tank | B344

    52 Gallon Marine Fresh Water Tank | B333

    Introducing the 52 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 a rectangular shape and a capacity of 52 gallons, this tank provides ample space for...

    $538.27
    Add to Cart
  • An image of a 11 Gallon Marine Holding Tank | BOAT16W

    52 Gallon Marine Fresh Water Tank | B315

    Introducing the 52 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
  • An image of a 19 Gallon Marine Fresh Water Tank | B480

    52 Gallon Marine Fresh Water Tank | B295

    Introducing the 52 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is specifically designed for marine use, making it perfect for boating and other water activities. With its rectangular shape, it offers a space-efficient solution for...

    $491.07
    Add to Cart
  • 52 Gallon Marine Water Tank MW-212. Technical drawing of a polyethylene water tank designed for marine vessels.

    52 Gallon Marine Water Tank MW-212

    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 52 Gallon Marine Water Tank, Part# MW-212, is engineered to meet the requirements of mobile...

    MSRP: $490.53
    $466.37
    Add to Cart
  • An image of a 23 Gallon Marine Fresh Water Tank | B450

    53 Gallon Marine Fresh Water Tank | B545

    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...

    $502.11
    Add to Cart
  • An image of a 18 Gallon Marine Holding Tank | B211

    53 Gallon Marine Fresh Water Tank | B312

    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 offers a space-efficient solution for...

    $491.07
    Add to Cart