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

  • 28 Gallon Marine Water Tank MW-260. Technical drawing of a polyethylene water tank designed for marine vessels.

    28 Gallon Marine Water Tank MW-260

    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-260, is engineered to meet the requirements of mobile...

    MSRP: $315.07
    $299.57
    Add to Cart
  • 28 Gallon Marine Water Tank MW-207. Technical drawing of a polyethylene water tank designed for marine vessels.

    28 Gallon Marine Water Tank MW-207

    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-207, is engineered to meet the requirements of mobile...

    MSRP: $294.82
    $280.30
    Add to Cart
  • An image of a 28 Gallon Marine Holding Tank | B437

    29 Gallon Marine Fresh Water Tank | B505

    Introducing the 29 Gallon Marine Fresh Water Tank by One Clarion! This rectangular tank is perfect for marine water storage and is designed to be portable, making it easy to transport and set up wherever you need it. With its above ground environment,...

    $339.43
    Add to Cart
  • An image of a 24 Gallon Marine Holding Tank | B402

    29 Gallon Marine Fresh Water Tank | B497

    Introducing the 29 Gallon Marine Fresh Water Tank by One Clarion. This rectangular tank is designed specifically for marine water and is perfect for both freshwater and saltwater environments. With its portable design, you can easily move and position...

    $350.48
    Add to Cart
  • An image of a 30 Gallon RV Holding Tank | RV22H

    29 Gallon Marine Fresh Water Tank | B423

    Introducing the 29 Gallon Marine Fresh Water Tank by One Clarion! This rectangular tank is designed specifically for marine water use, making it perfect for your fresh water needs. With its portable design, you can easily move and position the tank...

    $515.18
    Add to Cart
  • An image of a 50 Gallon RV Fresh Water Tank | RVB156

    29 Gallon Marine Fresh Water Tank | B421

    Introducing the 29 Gallon Marine Fresh Water Tank by One Clarion. This portable tank is perfect for marine water storage and is designed with a rectangular shape for easy placement. Made from durable polyethylene material, this tank is built to last and...

    $515.18
    Add to Cart
  • 29 Gallon Marine Water Tank MW-465. Technical drawing of a polyethylene water tank designed for marine vessels.

    29 Gallon Marine Water Tank MW-465

    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 29 Gallon Marine Water Tank, Part# MW-465, is engineered to meet the requirements of mobile...

    MSRP: $303.43
    $288.49
    Add to Cart
  • 29 Gallon Marine Water Tank MW-323. Technical drawing of a polyethylene water tank designed for marine vessels.

    29 Gallon Marine Water Tank MW-323

    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 29 Gallon Marine Water Tank, Part# MW-323, is engineered to meet the requirements of mobile...

    MSRP: $284.29
    $270.29
    Add to Cart
  • An image of a 9 Gallon Marine Holding Tank | B321

    30 Gallon Marine Fresh Water Tank | B502

    Upgrade your marine water storage with our 30 Gallon Marine Fresh Water Tank. This rectangular tank is designed for portable use and is suitable for above ground environments. Made from polyethylene and approved resin, this tank is durable and safe for...

    $327.38
    Add to Cart
  • An image of a 13 Gallon Marine Holding Tank | B218

    30 Gallon Marine Fresh Water Tank | B488

    The 30 Gallon Marine Fresh Water Tank by One Clarion is the perfect solution for your portable marine water storage needs. This rectangular tank is designed for above ground use and is made from high-quality polyethylene material in a natural white color...

    $327.38
    Add to Cart
  • An image of a 32 Gallon Marine Fresh Water Tank | B353

    30 Gallon Marine Fresh Water Tank | B481

    Introducing the 30 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 spacious capacity of 30 gallons. Made from...

    $327.38
    Add to Cart
  • An image of a 60 Gallon Marine Holding Tank | BOAT59W

    30 Gallon Marine Fresh Water Tank | B457

    The 30 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, this tank is designed to fit easily in various spaces. Whether you need to store water for...

    $456.93
    Add to Cart