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 48 Gallon Marine Fresh Water Tank | B293

    15 Gallon Marine Fresh Water Tank | B173

    Upgrade your marine vessel with the 16 Gallon Marine Fresh Water Tank from One Clarion. This portable tank is designed for above ground use and is made from ANSI/NSF 61 approved resin, ensuring safe and clean water storage. The rectangular shape and...

    $246.04
    Add to Cart
  • An image of a 20 Gallon Marine Holding Tank | B200

    15 Gallon Marine Fresh Water Tank | B131

    Introducing the 15 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 is easy to fit into tight spaces on...

    $232.98
    Add to Cart
  • Image of a 15 Gallon Trionic Marine Fresh Water Tank

    15 Gallon Trionic Marine Fresh Water Tank | WH-2015

    The 15 Gallon Trionic 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 boat...

    $301.26
    Add to Cart
  • 15 Gallon Marine Water Tank MW-543. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-543

    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 15 Gallon Marine Water Tank, Part# MW-543, is engineered to meet the requirements of mobile...

    MSRP: $346.52
    $329.47
    Add to Cart
  • 15 Gallon Marine Water Tank MW-489. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-489

    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 15 Gallon Marine Water Tank, Part# MW-489, is engineered to meet the requirements of mobile...

    MSRP: $185.41
    $176.28
    Add to Cart
  • 15 Gallon Marine Water Tank MW-366. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-366

    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 15 Gallon Marine Water Tank, Part# MW-366, is engineered to meet the requirements of mobile...

    MSRP: $246.93
    $234.77
    Add to Cart
  • 15 Gallon Marine Water Tank MW-355. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-355

    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 15 Gallon Marine Water Tank, Part# MW-355, is engineered to meet the requirements of mobile...

    MSRP: $182.38
    $173.40
    Add to Cart
  • 15 Gallon Marine Water Tank MW-328. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-328

    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 15 Gallon Marine Water Tank, Part# MW-328, is engineered to meet the requirements of mobile...

    MSRP: $300.67
    $285.87
    Add to Cart
  • 15 Gallon Marine Water Tank MW-327. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank MW-327

    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 15 Gallon Marine Water Tank, Part# MW-327, is engineered to meet the requirements of mobile...

    MSRP: $205.77
    $195.65
    Add to Cart
  • 15 Gallon Marine Water Tank ML-3. Technical drawing of a polyethylene water tank designed for marine vessels.

    15 Gallon Marine Water Tank ML-3

    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 15 Gallon Marine Water Tank, Part# ML-3, is engineered to meet the requirements of mobile...

    MSRP: $231.73
    $220.33
    Add to Cart
  • An image of a 18 Gallon Marine Fresh Water Tank | B412

    16 Gallon Marine Fresh Water Tank | BOAT36W

    The 16 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 boat or marine...

    $246.04
    Add to Cart
  • An image of a 25 Gallon Marine Fresh Water Tank | B163

    16 Gallon Marine Fresh Water Tank | B526

    The 16 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 is 26" in length, 14" in width, and 11" in height. It is not designed for...

    $280.18
    Add to Cart