Marine Water Tank

Marine Water Tanks

Marine Fresh Water Tanks

Durable, FDA-approved polyethylene marine fresh water tanks for potable water systems. These tanks are seamless, leak-resistant, and sized for tight compartments in boats and yachts. Use them for drinking water, galley water, showers, and general wash-down. Custom spin-weld fittings are included so you can connect to your existing pump, vent, and fill lines without awkward adapters.

Marine Holding Tanks

Resilient marine holding tanks designed for gray water and black water on boats, RVs, and live-aboard vessels. Built from thick-wall polyethylene, these tanks handle waste, soaps, and chemicals without corroding. We configure inlet, outlet, and vent fittings to suit your plumbing layout and can mirror many OEM marine holding tank footprints for straightforward replacement during a refit.

Marine Black Water Tanks

Coast Guard-style marine black water tanks for onboard waste systems. These tanks are built for durability and secure containment, with robust walls, reinforced fittings, and layouts that support proper venting and pump-out. Ideal for yachts, houseboats, workboats, and passenger vessels where reliable waste storage is critical for compliance and safety.

Custom Marine Water Tanks

Every hull, locker, and lazarette is different. That’s why most of our marine water tanks are built to order from heavy-duty, FDA-approved polyethylene. We work from your measurements and drawings to deliver a tank that drops into place and ties into your existing plumbing with minimal rework.

Our custom marine water tanks are:

• Roto-molded in one piece – no seams to leak, crack, or weep over time.
• Corrosion-proof – polyethylene won’t rust or pit in a saltwater environment.
• Chemical - and odor-resistant – suitable for potable water, gray water, and black water when specified correctly.
• Fittings-ready – we spin-weld threaded fittings, inspection ports, and vents where you need them.

If you’re working through a refit or a new build, we can review your current tank, match or increase capacity, and make sure the new marine tank meets the requirements for potable water or waste handling on your vessel. You get straightforward answers on lead times, pricing, and what information we need to finalize a drawing.

Additional Products

Storage Compartments

Rotomolded polyethylene storage compartments for clean, organized gear storage on deck or below. These corrosion-resistant lockers are available in multiple sizes and shapes and can be integrated alongside your marine water tanks to keep pumps, hoses, and hardware protected.

Battery Box

Heavy-duty marine battery boxes designed to handle vibration, spray, and harsh marine environments. These boxes help prevent tipping, shorting, and corrosion, protecting your starting and house batteries and keeping your electrical system safer and easier to service.

Custom Roto Mold Tanks

Need something outside standard marine water tank sizes? Our custom roto-molded tanks are built for marine, RV, and utility use where space is tight and loads are demanding. We can design tanks for ballast, specialized process water, or combined storage applications using long-lasting polyethylene construction.

Marine Water Tank FAQs

What types of marine water tanks do you offer for boats and yachts?

We supply three main types of marine water tanks: fresh water tanks for potable water, marine holding tanks for gray water, and black water tanks for sewage. All are rotomolded polyethylene tanks sized for tight marine spaces and can be built as custom boat water tanks to match your available footprint and plumbing layout.

Are these marine fresh water tanks safe for drinking water?

Yes. Our marine fresh water tanks are manufactured from FDA-approved polyethylene resin suitable for potable water when installed in an appropriate system. We use seamless construction to reduce contamination risk and can provide fittings for vent, fill, and suction lines to integrate with your existing marine water pump and filtration.

Can you build a custom boat water tank to match my existing tank?

In most cases, yes. For custom marine tanks we work from your dimensions, photos, and fitting locations. We can often mirror the footprint and capacity of an OEM boat water tank while improving wall thickness, access ports, or fitting locations. If you’re replacing a failed aluminum, steel, or fiberglass tank, we’ll help you convert to a polyethylene option that fits the same general space.

How do I choose the right size marine holding tank or black water tank?

Start with your typical crew size and how long you want to stay out without pumping out. From there we look at available space, mounting options, and vent/pipe routes. For many boats, a custom marine holding tank sized between one and three days of use works well. If you share a simple sketch or drawing, we’ll recommend a capacity and shape that balances volume, footprint, and weight.

Do your marine water tanks meet Coast Guard or ABYC requirements?

The polyethylene material and construction we use are compatible with systems designed to meet applicable USCG and ABYC guidelines for fresh and waste water. Final compliance depends on how the tank is installed, vented, supported, and connected. We’ll flag typical requirements—such as dedicated vent lines, secure mounting, and access for inspection—so you can coordinate with your boatyard or surveyor.

What fittings are available on marine fresh water and holding tanks?

We spin-weld polyethylene fittings in common NPT sizes (½", ¾", 1", and larger where needed) for fills, vents, pump suction, and level sensors. For marine black water tanks we can add inspection ports and pump-out connections. During quoting, we’ll ask where each hose runs so fittings land in the right place and you aren’t forced to use awkward adapters or long hose runs.

Can these marine tanks be used for both fresh water and waste?

The same base tank construction can be used for fresh water, gray water, or black water, but each tank must be dedicated to one service only. For potable water we keep fittings and accessories food-grade; for gray and black water we focus on venting, pump-out, and clean-out access. Let us know the intended use when you request a quote so we spec the correct configuration.

How are marine water tanks mounted and supported on a boat?

Most marine water tanks are installed on flat pads or cradles and restrained with straps, brackets, or framing. The goal is to support the full base of the tank and prevent movement in any direction when the vessel is underway. We’ll share recommended support and strapping guidelines for your specific tank so your yard can design a secure installation.

What is the typical lead time for a custom marine water tank?

Lead time depends on tank size and complexity, but most custom marine water tanks ship in a few weeks once drawings are approved. Standard sizes may ship faster. If you’re working toward a haul-out date or survey deadline, tell us up front and we’ll confirm what’s realistic before you commit.

How do I get a quote or drawing for a marine tank replacement?

Send us your rough dimensions, photos of the existing tank or space, and any requirements for capacity or fittings. From there we’ll recommend a marine fresh water, holding, or black water tank, provide a budget price, and—when needed—prepare a simple drawing for review before production. The goal is to answer your questions once, up front, so installation goes smoothly.