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

  • 41 Gallon RV Holding Tank H-345 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    41 Gallon RV Holding Tank H-345

    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 41 Gallon RV Holding Tank, Part# H-345, is engineered to meet the requirements of mobile...

    MSRP: $362.58
    $344.73
    Add to Cart
  • 41 Gallon RV Holding Tank H-245 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    41 Gallon RV Holding Tank H-245

    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 41 Gallon RV Holding Tank, Part# H-245, is engineered to meet the requirements of mobile...

    MSRP: $362.87
    $345.01
    Add to Cart
  • 41 Gallon RV Holding Tank H-209. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    41 Gallon RV Holding Tank H-209

    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 41 Gallon RV Holding Tank, Part# H-209, is engineered to meet the requirements of mobile...

    MSRP: $311.03
    $295.72
    Add to Cart
  • An image of a 69 Gallon Marine Fresh Water Tank | B444

    42 Gallon RV Fresh Water Tank | RVB510

    This 42-gallon Ronco RV fresh water tank (RVB510) provides reliable potable water storage for recreational vehicles. Measuring 24" x 22" x 20", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $318.34
    Add to Cart
  • An image of a 190 Gallon Marine Holding Tank | B506

    42 Gallon RV Fresh Water Tank | RVB443

    This 42-gallon Ronco RV fresh water tank (RVB443) provides reliable potable water storage for recreational vehicles. Measuring 24" x 24" x 19", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $318.34
    Add to Cart
  • An image of a 19 Gallon RV Holding Tank | RV16H

    42 Gallon RV Fresh Water Tank | RVB380

    This 42-gallon Ronco RV fresh water tank (RVB380) provides reliable potable water storage for recreational vehicles. Measuring 40" x 26 3/4" x 10", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $381.60
    Add to Cart
  • An image of a 41 Gallon Marine Fresh Water Tank | BOAT47W

    42 Gallon RV Fresh Water Tank | RVB237

    This 42-gallon Ronco RV fresh water tank (RVB237) provides reliable potable water storage for recreational vehicles. Measuring 36" x 25" x 12", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $287.21
    Add to Cart
  • An image of a 115 Gallon RV Fresh Water Tank | B328

    42 Gallon RV Fresh Water Tank | RVB182

    This 42-gallon Ronco RV fresh water tank (RVB182) provides reliable potable water storage for recreational vehicles. Measuring 46" x 18" x 13", it is sized to fit a range of RV builds and offers dependable water capacity for trips of all lengths...

    $351.48
    Add to Cart
  • An image of a 4 Gallon Marine Fresh Water Tank | B269

    42 Gallon RV Holding Tank | RV74H

    This 42-gallon Ronco RV holding tank (RV74H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 39" x 17" x 16", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $327.38
    Add to Cart
  • An image of a 35 Gallon Marine Holding Tank | BOAT38W

    42 Gallon RV Holding Tank | RV61H

    This 42-gallon Ronco RV holding tank (RV61H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 45" x 25" x 12", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $456.93
    Add to Cart
  • An image of a 47 Gallon Marine Fresh Water Tank | BOAT33W

    42 Gallon RV Holding Tank | RV21H

    This 42-gallon Ronco RV holding tank (RV21H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 40" x 25" x 13", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $397.67
    Add to Cart
  • An image of a 35 Gallon Marine Holding Tank | B371

    42 Gallon RV Holding Tank | RV106H

    This 42-gallon Ronco RV holding tank (RV106H) is designed for blackwater and greywater waste storage in recreational vehicles. Measuring 36" x 20" x 17", it fits common RV underbelly and compartment configurations while providing reliable waste...

    $316.33
    Add to Cart
  • An image of a 69 Gallon Marine Holding Tank | B444

    42 Gallon Marine Fresh Water Tank | B510

    This 42-gallon Ronco marine fresh water tank (B510) is built for onboard potable water storage on boats and watercraft. Measuring 24" x 22" x 20", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $431.82
    Add to Cart
  • An image of a 42 Gallon Marine Fresh Water Tank | B443

    42 Gallon Marine Holding Tank | B510

    This 42-gallon Ronco marine holding tank (B510) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 24" x 22" x 20", it is designed to fit common marine compartment layouts while providing dependable waste...

    $431.82
    Add to Cart
  • An image of a 29 Gallon Marine Fresh Water Tank | B505

    42 Gallon Marine Fresh Water Tank | B443

    This 42-gallon Ronco marine fresh water tank (B443) is built for onboard potable water storage on boats and watercraft. Measuring 24" x 24" x 19", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $408.72
    Add to Cart
  • An image of a 29 Gallon Marine Holding Tank | B505

    42 Gallon Marine Holding Tank | B443

    This 42-gallon Ronco marine holding tank (B443) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 24" x 24" x 19", it is designed to fit common marine compartment layouts while providing dependable waste...

    $408.72
    Add to Cart
  • An image of a 33 Gallon RV Holding Tank | RV15H

    42 Gallon Marine Fresh Water Tank | B380

    This 42-gallon Ronco marine fresh water tank (B380) is built for onboard potable water storage on boats and watercraft. Measuring 40" x 26 3/4" x 10", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on...

    $408.72
    Add to Cart
  • An image of a 12 Gallon RV Fresh Water Tank | RV14W

    42 Gallon Marine Holding Tank | B380

    This 42-gallon Ronco marine holding tank (B380) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 40" x 26 3/4" x 10", it is designed to fit common marine compartment layouts while providing dependable waste...

    $408.72
    Add to Cart
  • An image of a 41 Gallon Marine Holding Tank | BOAT47W

    42 Gallon Marine Fresh Water Tank | B237

    This 42-gallon Ronco marine fresh water tank (B237) is built for onboard potable water storage on boats and watercraft. Measuring 36" x 25" x 12", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $408.72
    Add to Cart
  • An image of a 58 Gallon Marine Fresh Water Tank | BOAT44W

    42 Gallon Marine Holding Tank | B237

    This 42-gallon Ronco marine holding tank (B237) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 36" x 25" x 12", it is designed to fit common marine compartment layouts while providing dependable waste...

    $408.72
    Add to Cart
  • An image of a 115 Gallon Marine Fresh Water Tank | B328

    42 Gallon Marine Fresh Water Tank | B182

    This 42-gallon Ronco marine fresh water tank (B182) is built for onboard potable water storage on boats and watercraft. Measuring 46" x 18" x 13", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $408.72
    Add to Cart
  • An image of a 80 Gallon RV Fresh Water Tank | B327

    42 Gallon Marine Holding Tank | B182

    This 42-gallon Ronco marine holding tank (B182) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 46" x 18" x 13", it is designed to fit common marine compartment layouts while providing dependable waste...

    $408.72
    Add to Cart
  • An image of a 115 Gallon Marine Holding Tank | B328

    42 Gallon Marine Fresh Water Tank | B119

    This 42-gallon Ronco marine fresh water tank (B119) is built for onboard potable water storage on boats and watercraft. Measuring 60" x 18" x 14", it fits a wide range of vessel layouts and provides reliable fresh water capacity for extended trips on the...

    $432.83
    Add to Cart
  • An image of a 80 Gallon Marine Fresh Water Tank | B327

    42 Gallon Marine Holding Tank | B119

    This 42-gallon Ronco marine holding tank (B119) is purpose-built for blackwater and greywater waste storage on boats and watercraft. Measuring 60" x 18" x 14", it is designed to fit common marine compartment layouts while providing dependable waste...

    $432.83
    Add to Cart
  • 42 Gallon RV Water Tank W-204. Technical drawing of a polyethylene water tank designed for your rv.

    42 Gallon RV Water Tank W-204

    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 42 Gallon RV Water Tank, Part# W-204, is engineered to meet the requirements of mobile water...

    MSRP: $207.36
    $197.15
    Add to Cart
  • 42 Gallon Marine Water Tank MW-464. Technical drawing of a polyethylene water tank designed for marine vessels.

    42 Gallon Marine Water Tank MW-464

    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 42 Gallon Marine Water Tank, Part# MW-464, is engineered to meet the requirements of mobile...

    MSRP: $379.36
    $360.69
    Add to Cart
  • 42 Gallon Marine Water Tank MW-405. Technical drawing of a polyethylene water tank designed for marine vessels.

    42 Gallon Marine Water Tank MW-405

    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 42 Gallon Marine Water Tank, Part# MW-405, is engineered to meet the requirements of mobile...

    MSRP: $618.00
    $587.57
    Add to Cart
  • 42 Gallon Marine Water Tank MW-204. Technical drawing of a polyethylene water tank designed for marine vessels.

    42 Gallon Marine Water Tank MW-204

    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 42 Gallon Marine Water Tank, Part# MW-204, is engineered to meet the requirements of mobile...

    MSRP: $420.97
    $400.25
    Add to Cart
  • 42 Gallon RV Holding Tank H-498 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    42 Gallon RV Holding Tank H-498

    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 42 Gallon RV Holding Tank, Part# H-498, is engineered to meet the requirements of mobile...

    MSRP: $323.99
    $308.04
    Add to Cart
  • 42 Gallon RV Holding Tank H-445 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    42 Gallon RV Holding Tank H-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 42 Gallon RV Holding Tank, Part# H-445, is engineered to meet the requirements of mobile...

    MSRP: $285.11
    $271.08
    Add to Cart
  • 42 Gallon RV Holding Tank H-239 . Technical drawing of a polyethylene holding tank designed for your rv and camper.

    42 Gallon RV Holding Tank H-239

    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 42 Gallon RV Holding Tank, Part# H-239, is engineered to meet the requirements of mobile...

    MSRP: $311.03
    $295.72
    Add to Cart
  • 42 Gallon RV Holding Tank H-203. Technical drawing of a polyethylene holding tank designed for your rv and camper.

    42 Gallon RV Holding Tank H-203

    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 42 Gallon RV Holding Tank, Part# H-203, is engineered to meet the requirements of mobile...

    MSRP: $285.11
    $271.08
    Add to Cart