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 36 Gallon Marine Holding Tank | B340

    28 Gallon Marine Fresh Water Tank | B394

    The 28 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...

    $421.77
    Add to Cart
  • An image of a 23 Gallon Marine Fresh Water Tank | B498

    28 Gallon Marine Fresh Water Tank | B374

    Introducing the 28 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 and dimensions of 27" length x 24" width x 19" height, it provides...

    $397.67
    Add to Cart
  • An image of a 254 Gallon PE Ronco White Rectangular Open Top Tank | 48X36X36PE

    28 Gallon Marine Fresh Water Tank | B335

    Introducing the 28 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 and dimensions of 52" length x 12" width x 11" height, it provides...

    $386.63
    Add to Cart
  • An image of a 9 Gallon Marine Holding Tank | B358

    28 Gallon Marine Fresh Water Tank | B273

    Introducing the 28 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...

    $350.48
    Add to Cart
  • An image of a 28 Gallon Marine Fresh Water Tank | B169

    28 Gallon Marine Fresh Water Tank | B239

    The 28 Gallon Marine Fresh Water Tank offered by One Clarion is a versatile and portable solution for your marine water storage needs. With its rectangular tank shape, it is designed to fit easily in various spaces. This tank is specifically designed for...

    $350.48
    Add to Cart
  • An image of a 260 Gallon PP Ronco White Cylindrical Open Top Tank | 260PP

    28 Gallon Marine Fresh Water Tank | B206

    Introducing the 28 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 space-saving solution for storing fresh water on your...

    $397.67
    Add to Cart
  • An image of a 27 Gallon Marine Fresh Water Tank | B420

    28 Gallon Marine Fresh Water Tank | B170

    Upgrade your marine vessel with the 28 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...

    $386.63
    Add to Cart
  • 28 Gallon Marine Fresh Water Tank | B169

    Introducing the 28 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is perfect for marine environments and is designed to hold fresh water. With a rectangular shape and a capacity of 28 gallons, this tank is spacious enough to meet your...

    $386.63
    Add to Cart
  • An image of a 28 Gallon Marine Holding Tank | B206

    28 Gallon Marine Fresh Water Tank | B161

    Upgrade your marine vessel with the 28 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...

    $326.38
    Add to Cart
  • 28 Gallon Marine Water Tank MW-513. Technical drawing of a polyethylene water tank designed for marine vessels.

    28 Gallon Marine Water Tank MW-513

    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 28 Gallon Marine Water Tank, Part# MW-513, is engineered to meet the requirements of mobile...

    MSRP: $606.21
    $576.37
    Add to Cart
  • 28 Gallon Marine Water Tank MW-468. Technical drawing of a polyethylene water tank designed for marine vessels.

    28 Gallon Marine Water Tank MW-468

    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 28 Gallon Marine Water Tank, Part# MW-468, is engineered to meet the requirements of mobile...

    MSRP: $382.95
    $364.11
    Add to Cart
  • 28 Gallon Marine Water Tank MW-45. Technical drawing of a polyethylene water tank designed for marine vessels.

    28 Gallon Marine Water Tank MW-45

    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 28 Gallon Marine Water Tank, Part# MW-45, is engineered to meet the requirements of mobile...

    MSRP: $268.84
    $255.60
    Add to Cart