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

  • An image of a 15 Gallon RV Fresh Water Tank | RVB320

    47 Gallon RV Holding Tank | RV97H

    This 47-gallon Ronco RV holding tank (RV97H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 35" x 39" x 16", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $562.37
    Add to Cart
  • An image of a 58 Gallon Marine Holding Tank | BOAT60W

    47 Gallon Marine Fresh Water Tank | BOAT33W

    This 47-gallon Ronco marine fresh water tank (BOAT33W) is built for onboard potable water storage on boats and watercraft. Measuring 40 1/2" x 25 1/4" x 12", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $421.77
    Add to Cart
  • An image of a 60 Gallon Marine Fresh Water Tank | BOAT59W

    47 Gallon Marine Holding Tank | BOAT33W

    This 47-gallon Ronco marine holding tank (BOAT33W) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 40 1/2" x 25 1/4" x 12", it is designed to fit common marine compartment layouts while providing dependable...

    $421.77
    Add to Cart
  • An image of a 43 Gallon Marine Holding Tank | BOAT22W

    47 Gallon Marine Fresh Water Tank | B507

    This 47-gallon Ronco marine fresh water tank (B507) is built for onboard potable water storage on boats and watercraft. Measuring 33 1/4" x 24 1/2" x 15", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $431.82
    Add to Cart
  • An image of a 8 Gallon Marine Fresh Water Tank | BOAT21W

    47 Gallon Marine Holding Tank | B507

    This 47-gallon Ronco marine holding tank (B507) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 33 1/4" x 24 1/2" x 15", it is designed to fit common marine compartment layouts while providing dependable...

    $431.82
    Add to Cart
  • 47 Gallon RV Water Tank W-537. Technical drawing of a polyethylene water tank designed for your rv.

    47 Gallon RV Water Tank W-537

    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 47 Gallon RV Water Tank, Part# W-537, is engineered to meet the requirements of mobile water...

    MSRP: $336.95
    $320.36
    Add to Cart
  • 47 Gallon Marine Water Tank MW-537. Technical drawing of a polyethylene water tank designed for marine vessels.

    47 Gallon Marine Water Tank MW-537

    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 47 Gallon Marine Water Tank, Part# MW-537, is engineered to meet the requirements of mobile...

    MSRP: $845.26
    $803.65
    Add to Cart
  • 47 Gallon RV Holding Tank H-585 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    47 Gallon RV Holding Tank H-585

    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 47 Gallon RV Holding Tank, Part# H-585, is engineered to meet the requirements of mobile...

    MSRP: $311.03
    $295.72
    Add to Cart
  • 47 Gallon RV Holding Tank H-430 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    47 Gallon RV Holding Tank H-430

    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 47 Gallon RV Holding Tank, Part# H-430, is engineered to meet the requirements of mobile...

    MSRP: $362.87
    $345.01
    Add to Cart
  • 47 Gallon RV Holding Tank H-376 [OR] . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    47 Gallon RV Holding Tank H-376 [OR]

    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 47 Gallon RV Holding Tank, Part# H-376 [OR], is engineered to meet the requirements of mobile...

    MSRP: $362.87
    $345.01
    Add to Cart
  • 47 Gallon RV Holding Tank H-359 [OR] . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    47 Gallon RV Holding Tank H-359 [OR]

    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 47 Gallon RV Holding Tank, Part# H-359 [OR], is engineered to meet the requirements of mobile...

    MSRP: $349.91
    $332.68
    Add to Cart
  • An image of a 17 Gallon RV Fresh Water Tank | RV36W

    48 Gallon RV Fresh Water Tank | RVB491

    This 48-gallon Ronco RV fresh water tank (RVB491) provides reliable potable water storage for recreational vehicles. Measuring 39" x 27 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 lengths...

    $454.92
    Add to Cart
  • An image of a 11 Gallon Marine Holding Tank | BOAT14W

    48 Gallon RV Fresh Water Tank | RVB306

    This 48-gallon Ronco RV fresh water tank (RVB306) provides reliable potable water storage for recreational vehicles. Measuring 45 1/2" x 24 1/4" x 11", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $463.95
    Add to Cart
  • An image of a 30 Gallon RV Fresh Water Tank | RV24W

    48 Gallon RV Fresh Water Tank | RVB229

    This 48-gallon Ronco RV fresh water tank (RVB229) provides reliable potable water storage for recreational vehicles. Measuring 68 1/2" x 27" x 7", 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 45 Gallon Marine Holding Tank | B376

    48 Gallon RV Fresh Water Tank | RV9W

    This 48-gallon Ronco RV fresh water tank (RV9W) provides reliable potable water storage for recreational vehicles. Measuring 48" x 20" x 12", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $425.79
    Add to Cart
  • An image of a 20 Gallon Marine Fresh Water Tank | BOAT39W

    48 Gallon RV Holding Tank | RV92H

    This 48-gallon Ronco RV holding tank (RV92H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 60" x 25" x 11", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $562.37
    Add to Cart
  • An image of a 30 Gallon RV Holding Tank | RV39H

    48 Gallon RV Holding Tank | RV60H

    This 48-gallon Ronco RV holding tank (RV60H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 48" x 28" x 13", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $386.63
    Add to Cart
  • An image of a 9 Gallon RV Holding Tank | RV36H

    48 Gallon Marine Fresh Water Tank | B491

    This 48-gallon Ronco marine fresh water tank (B491) is built for onboard potable water storage on boats and watercraft. Measuring 39" x 27 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 9 Gallon RV Holding Tank | RV35H

    48 Gallon Marine Holding Tank | B491

    This 48-gallon Ronco marine holding tank (B491) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 39" x 27 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 22 Gallon Marine Fresh Water Tank | B463

    48 Gallon Marine Fresh Water Tank | B384

    This 48-gallon Ronco marine fresh water tank (B384) is built for onboard potable water storage on boats and watercraft. Measuring 36" x 22 3/4" x 17 1/2", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended...

    $550.32
    Add to Cart
  • An image of a 22 Gallon Marine Holding Tank | B463

    48 Gallon Marine Holding Tank | B384

    This 48-gallon Ronco marine holding tank (B384) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 36" x 22 3/4" x 17 1/2", it is designed to fit common marine compartment layouts while providing dependable...

    $550.32
    Add to Cart
  • An image of a 3 Gallon Marine Fresh Water Tank | BOAT13W

    48 Gallon Marine Fresh Water Tank | B306

    This 48-gallon Ronco marine fresh water tank (B306) is built for onboard potable water storage on boats and watercraft. Measuring 45 1/2" x 24 1/4" x 11", 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 3 Gallon Marine Holding Tank | BOAT13W

    48 Gallon Marine Holding Tank | B306

    This 48-gallon Ronco marine holding tank (B306) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 45 1/2" x 24 1/4" x 11", it is designed to fit common marine compartment layouts while providing dependable...

    $491.07
    Add to Cart
  • An image of a 47 Gallon Marine Fresh Water Tank | B507

    48 Gallon Marine Fresh Water Tank | B293

    This 48-gallon Ronco marine fresh water tank (B293) is built for onboard potable water storage on boats and watercraft. Measuring 34" x 24" x 19", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $573.42
    Add to Cart
  • An image of a 47 Gallon Marine Holding Tank | B507

    48 Gallon Marine Holding Tank | B293

    This 48-gallon Ronco marine holding tank (B293) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 34" x 24" x 19", it is designed to fit common marine compartment layouts while providing dependable waste...

    $573.42
    Add to Cart
  • An image of a 20 Gallon RV Holding Tank | RV24H

    48 Gallon Marine Fresh Water Tank | B229

    This 48-gallon Ronco marine fresh water tank (B229) is built for onboard potable water storage on boats and watercraft. Measuring 68 1/2" x 27" x 7", 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 11 Gallon RV Fresh Water Tank | RV23W

    48 Gallon Marine Holding Tank | B229

    This 48-gallon Ronco marine holding tank (B229) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 68 1/2" x 27" x 7", it is designed to fit common marine compartment layouts while providing dependable waste...

    $491.07
    Add to Cart
  • 48 Gallon RV Water Tank W-514. Technical drawing of a polyethylene water tank designed for your rv.

    48 Gallon RV Water Tank W-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 RV Water Tank, Part# W-514, is engineered to meet the requirements of mobile water...

    MSRP: $414.71
    $394.29
    Add to Cart
  • 48 Gallon RV Water Tank W-445. Technical drawing of a polyethylene water tank designed for your rv.

    48 Gallon RV Water Tank W-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 RV Water Tank, Part# W-445, is engineered to meet the requirements of mobile water...

    MSRP: $349.91
    $332.68
    Add to Cart
  • 48 Gallon RV Water Tank W-319. Technical drawing of a polyethylene water tank designed for your rv.

    48 Gallon RV Water Tank W-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 RV Water Tank, Part# W-319, is engineered to meet the requirements of mobile water...

    MSRP: $285.11
    $271.08
    Add to Cart
  • 48 Gallon RV Water Tank W-279. Technical drawing of a polyethylene water tank designed for your rv.

    48 Gallon RV Water Tank W-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 RV Water Tank, Part# W-279, is engineered to meet the requirements of mobile water...

    MSRP: $311.03
    $295.72
    Add to Cart
  • 48 Gallon Marine Water Tank MW-79. Technical drawing of a polyethylene water tank designed for marine vessels.

    48 Gallon Marine Water Tank MW-79

    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-79, is engineered to meet the requirements of mobile...

    MSRP: $406.31
    $386.31
    Add to Cart