Marine and RV Water and Holding Tanks for Sale

Pick the size, the shape, and the fitting locations to make a perfect fit for your Marine or RV Water and Holding Tank replacement.   You won’t find better-made RV or Marine holding 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. The bottom line: These tanks are nearly unbreakable and are built to go the distance, at sea or on the road.

Fittings: You 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 RV freshwater tanks, RV holding tanks, RV black water holding tanks, RV waste holding tanks, Marine fresh water tanks, Marine holding tanks, and more!

We have 100's of sizes ranging from 2 gallons, 40 gallons, 50 gallons, 100 gallons, up to 250 gallons for these marine and rv fresh water and holding tanks.

  • Marine Holding Tanks
  • Marine Water Tanks
  • RV holding Tanks
  • RV Water Tanks
  • RV Black Water Tanks

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RV & Marine Tanks

  • 48 Gallon Marine Water Tank MW-514. Technical drawing of a polyethylene water tank designed for marine vessels.

    48 Gallon Marine Water Tank MW-514

    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 48 Gallon Marine Water Tank, Part# MW-514, is engineered to meet the requirements of mobile...

    MSRP: $426.10
    $405.12
    Add to Cart
  • 48 Gallon Marine Water Tank MW-445. Technical drawing of a polyethylene water tank designed for marine vessels.

    48 Gallon Marine Water Tank MW-445

    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 48 Gallon Marine Water Tank, Part# MW-445, is engineered to meet the requirements of mobile...

    MSRP: $576.70
    $548.31
    Add to Cart
  • 48 Gallon Marine Water Tank MW-319. Technical drawing of a polyethylene water tank designed for marine vessels.

    48 Gallon Marine Water Tank MW-319

    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 48 Gallon Marine Water Tank, Part# MW-319, is engineered to meet the requirements of mobile...

    MSRP: $453.21
    $430.90
    Add to Cart
  • 48 Gallon Marine Water Tank MW-279. Technical drawing of a polyethylene water tank designed for marine vessels.

    48 Gallon Marine Water Tank MW-279

    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 48 Gallon Marine Water Tank, Part# MW-279, is engineered to meet the requirements of mobile...

    MSRP: $531.08
    $504.94
    Add to Cart
  • 48 Gallon RV Holding Tank H-526 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    48 Gallon RV Holding Tank H-526

    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 48 Gallon RV Holding Tank, Part# H-526, is engineered to meet the requirements of mobile...

    MSRP: $285.11
    $271.08
    Add to Cart
  • 48 Gallon RV Holding Tank H-311 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    48 Gallon RV Holding Tank H-311

    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 48 Gallon RV Holding Tank, Part# H-311, is engineered to meet the requirements of mobile...

    MSRP: $323.99
    $308.04
    Add to Cart
  • An image of a 52 Gallon Marine Fresh Water Tank | B422

    49 Gallon Marine Fresh Water Tank | B482

    This 49-gallon Ronco marine fresh water tank (B482) is built for onboard potable water storage on boats and watercraft. Measuring 43 1/2" x 21" x 16", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $480.02
    Add to Cart
  • An image of a 52 Gallon Marine Holding Tank | B422

    49 Gallon Marine Holding Tank | B482

    This 49-gallon Ronco marine holding tank (B482) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 43 1/2" x 21" x 16", it is designed to fit common marine compartment layouts while providing dependable waste...

    $480.02
    Add to Cart
  • 49 Gallon RV Water Tank W-461. Technical drawing of a polyethylene water tank designed for your rv.

    49 Gallon RV Water Tank W-461

    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 49 Gallon RV Water Tank, Part# W-461, is engineered to meet the requirements of mobile water...

    MSRP: $272.15
    $258.76
    Add to Cart
  • 49 Gallon Marine Water Tank MW-506. Technical drawing of a polyethylene water tank designed for marine vessels.

    49 Gallon Marine Water Tank MW-506

    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 49 Gallon Marine Water Tank, Part# MW-506, is engineered to meet the requirements of mobile...

    MSRP: $556.33
    $528.94
    Add to Cart
  • 49 Gallon Marine Water Tank MW-461. Technical drawing of a polyethylene water tank designed for marine vessels.

    49 Gallon Marine Water Tank MW-461

    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 49 Gallon Marine Water Tank, Part# MW-461, is engineered to meet the requirements of mobile...

    MSRP: $490.52
    $466.37
    Add to Cart
  • 49 Gallon RV Holding Tank H-608. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    49 Gallon RV Holding Tank H-608

    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 49 Gallon RV Holding Tank, Part# H-608, is engineered to meet the requirements of mobile...

    MSRP: $401.75
    $381.97
    Add to Cart
  • An image of a 70 Gallon Marine Fresh Water Tank | B343

    50 Gallon RV Fresh Water Tank | RVB465

    This 50-gallon Ronco RV fresh water tank (RVB465) provides reliable potable water storage for recreational vehicles. Measuring 59 3/4" x 18 1/2" x 11 3/4", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all...

    $386.63
    Add to Cart
  • An image of a 36 Gallon Marine Holding Tank | B254

    50 Gallon RV Fresh Water Tank | RVB416

    This 50-gallon Ronco RV fresh water tank (RVB416) provides reliable potable water storage for recreational vehicles. Measuring 50" x 16" x 16", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $341.43
    Add to Cart
  • An image of a 32 Gallon Marine Fresh Water Tank | B449

    50 Gallon RV Fresh Water Tank | RVB308

    This 50-gallon Ronco RV fresh water tank (RVB308) provides reliable potable water storage for recreational vehicles. Measuring 64" x 22" x 9 1/8", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $454.92
    Add to Cart
  • An image of a 32 Gallon RV Fresh Water Tank | RV26W

    50 Gallon RV Fresh Water Tank | RVB210

    This 50-gallon Ronco RV fresh water tank (RVB210) provides reliable potable water storage for recreational vehicles. Measuring 33" x 27" x 14", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $454.92
    Add to Cart
  • An image of a 7 Gallon Marine Holding Tank | B395

    50 Gallon RV Fresh Water Tank | RVB156

    This 50-gallon Ronco RV fresh water tank (RVB156) provides reliable potable water storage for recreational vehicles. Measuring 40" x 20" x 16", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $454.92
    Add to Cart
  • An image of a 20 Gallon Marine Holding Tank | BOAT39W

    50 Gallon RV Holding Tank | RV91H

    This 50-gallon Ronco RV holding tank (RV91H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 70" x 25" x 12", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $562.37
    Add to Cart
  • An image of a 42 Gallon RV Fresh Water Tank | RVB510

    50 Gallon Marine Fresh Water Tank | BOAT8W

    This 50-gallon Ronco marine fresh water tank (BOAT8W) is built for onboard potable water storage on boats and watercraft. Measuring 60 1/4" x 20 1/8" x 11", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $456.93
    Add to Cart
  • An image of a 47 Gallon RV Fresh Water Tank | RVB507

    50 Gallon Marine Holding Tank | BOAT8W

    This 50-gallon Ronco marine holding tank (BOAT8W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 60 1/4" x 20 1/8" x 11", it is designed to fit common marine compartment layouts while providing dependable...

    $456.93
    Add to Cart
  • An image of a 70 Gallon Marine Holding Tank | B343

    50 Gallon Marine Fresh Water Tank | B465

    This 50-gallon Ronco marine fresh water tank (B465) is built for onboard potable water storage on boats and watercraft. Measuring 59 3/4" x 18 1/2" x 11 3/4", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $491.07
    Add to Cart
  • An image of a 27 Gallon Marine Fresh Water Tank | B342

    50 Gallon Marine Holding Tank | B465

    This 50-gallon Ronco marine holding tank (B465) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 59 3/4" x 18 1/2" x 11 3/4", it is designed to fit common marine compartment layouts while providing dependable...

    $491.07
    Add to Cart
  • An image of a 20 Gallon Marine Fresh Water Tank | B253

    50 Gallon Marine Fresh Water Tank | B416

    This 50-gallon Ronco marine fresh water tank (B416) is built for onboard potable water storage on boats and watercraft. Measuring 50" x 16" x 16", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $491.07
    Add to Cart
  • An image of a 20 Gallon Marine Holding Tank | B253

    50 Gallon Marine Holding Tank | B416

    This 50-gallon Ronco marine holding tank (B416) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 50" x 16" x 16", it is designed to fit common marine compartment layouts while providing dependable waste...

    $491.07
    Add to Cart
  • An image of a 32 Gallon Marine Holding Tank | B449

    50 Gallon Marine Fresh Water Tank | B308

    This 50-gallon Ronco marine fresh water tank (B308) is built for onboard potable water storage on boats and watercraft. Measuring 64" x 22" x 9 1/8", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $491.07
    Add to Cart
  • An image of a 95 Gallon Marine Holding Tank | B448

    50 Gallon Marine Holding Tank | B308

    This 50-gallon Ronco marine holding tank (B308) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 64" x 22" x 9 1/8", it is designed to fit common marine compartment layouts while providing dependable waste...

    $491.07
    Add to Cart
  • An image of a 13 Gallon RV Holding Tank | RV26H

    50 Gallon Marine Fresh Water Tank | B210

    This 50-gallon Ronco marine fresh water tank (B210) is built for onboard potable water storage on boats and watercraft. Measuring 33" x 27" x 14", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $466.97
    Add to Cart
  • An image of a 25 Gallon RV Holding Tank | RV25H

    50 Gallon Marine Holding Tank | B210

    This 50-gallon Ronco marine holding tank (B210) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 33" x 27" x 14", it is designed to fit common marine compartment layouts while providing dependable waste...

    $466.97
    Add to Cart
  • An image of a 95 Gallon Marine Fresh Water Tank | B448

    50 Gallon Marine Fresh Water Tank | B198

    This 50-gallon Ronco marine fresh water tank (B198) is built for onboard potable water storage on boats and watercraft. Measuring 31 1/4" x 22" x 19", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $550.32
    Add to Cart
  • An image of a 19 Gallon Marine Fresh Water Tank | B447

    50 Gallon Marine Holding Tank | B198

    This 50-gallon Ronco marine holding tank (B198) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 31 1/4" x 22" x 19", it is designed to fit common marine compartment layouts while providing dependable waste...

    $550.32
    Add to Cart
  • An image of a 20 Gallon RV Fresh Water Tank | RVB234

    50 Gallon Marine Fresh Water Tank | B178

    This 50-gallon Ronco marine fresh water tank (B178) is built for onboard potable water storage on boats and watercraft. Measuring 60 3/4" x 33 1/2" x 14 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $667.82
    Add to Cart
  • An image of a 20 Gallon RV Fresh Water Tank | RVB233

    50 Gallon Marine Holding Tank | B178

    This 50-gallon Ronco marine holding tank (B178) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 60 3/4" x 33 1/2" x 14 1/2", it is designed to fit common marine compartment layouts while providing dependable...

    $667.82
    Add to Cart