PLUMBING and TANKS
A reliable boat water and holding-tank system involves much more than simply installing a couple of tanks.
The projects below cover the major components of freshwater and wastewater systems on sailboats and trawlers, including freshwater tanks, water filtration, pumps, plumbing, black-water holding tanks, tank vents, deck fittings and thru-hulls. I also cover designing and installing complete water systems during a boat restoration, including tank placement, access for maintenance and making efficient use of limited space. Whether you’re replacing an aging system or starting with a stripped hull, these projects demonstrate practical approaches to building safe, serviceable and reliable marine plumbing and water systems.
Planning Freshwater and Holding Tank Installation with Full-Size Mockups
Fitting freshwater tanks, waste holding tanks, batteries, pumps and other systems into the limited space of a small trawler requires careful planning before expensive components are ordered. In this video, I use pink EPS foam to build full-size mockups of the water and waste tanks, allowing me to test their size, shape, fittings and location directly inside the engine compartment. I show how the mockups help determine tank capacity, plumbing connections and clearances while leaving enough room for the engine, lithium batteries, pumps and other equipment. This approach provides a practical way to design a boat’s freshwater and holding-tank system around the available space before purchasing or installing the actual tanks.
Ordering Custom Marine Freshwater and Holding Tanks
Ordering custom freshwater and waste holding tanks can be one of the more expensive parts of rebuilding a boat’s plumbing system, so dimensions, fittings and specifications need to be correct before placing the order. In this video, I document my experience ordering custom polyethylene tanks from Ronco Plastics, including tank design, fittings, cost, freight, shipping damage and the replacement process. I show what arrived, the damage I found during inspection, and the customer-service problems that followed. The project provides practical lessons on ordering custom marine water and holding tanks, inspecting them immediately upon delivery, documenting damage and understanding shipping and replacement policies before spending money on a custom tank system.
How to Lift a Large Boat Off a Trailer Without a Crane
Removing a large boat from its trailer doesn’t necessarily require a marina travel lift, crane or forklift. In this video, I demonstrate how I lifted a 4,200-pound bare hull Albin 27 trawler off a triple-axle trailer using a GoHoist A-frame boat hoist, keel support and adjustable boat stands. I cover lifting the hull, positioning and leveling the boat on stands, and safely moving the trailer out from underneath it. Getting the boat off the trailer provides complete access to the hull while also allowing the trailer to be serviced, painted and rewired. The project demonstrates a practical approach to lifting and blocking a larger trailerable sailboat or trawler at home during a major boat restoration.
Designing Plumbing and Tankage for a Pocket Trawler
Building a pocket trawler from a stripped hull requires planning the freshwater, wastewater and plumbing systems as part of the overall boat design, not as individual components added later. In this video, I walk through the plumbing and tankage planned for my Albin 27 Great Loop trawler, including freshwater storage tanks, a black-water holding tank, electric macerating marine toilet, pumps, plumbing and hot-water system. I also discuss how tank capacity, component location, available space, electrical requirements and access for future maintenance affect the design. The project demonstrates how I approach building a complete freshwater and waste system for a small cruising trawler where space, reliability and serviceability are critical.
Designing a Full-Size Bathroom and Shower for a Pocket Trawler
A small cruising boat doesn’t necessarily have to settle for a cramped wet head. In this video, I plan the complete rebuild of the bathroom on my 27-foot pocket trawler, expanding the original compartment into approximately 20 square feet with a separate shower, marine toilet and sink. I work through the layout, plumbing requirements, available space and material choices needed to create a practical dry head for long-term cruising. The project also covers using Coosa Board, fiberglass and epoxy to construct waterproof bulkheads and surfaces that are durable and easy to clean. This is the starting point for building a complete boat bathroom, shower and plumbing system within the limited space of a pocket trawler.
Installing a Boat Shower Pan, Drain and Plumbing
Installing a larger shower in a small trawler requires fitting the shower pan and drain into an existing structure while leaving enough room for the plumbing underneath. In this video, I install the shower pan for the enlarged bathroom on my Albin 27, including modifying the subfloor, positioning and dry-fitting the pan, and selecting the correct marine shower drain and plumbing fittings. I show how I enlarge the opening for the drain, use backing blocks to achieve a flush installation, and adapt the drain from 3/4-inch to 1-inch hose. The project demonstrates the practical plumbing and fabrication required to install a dedicated shower in a small sailboat or pocket trawler.
How a Marine Plumbing System Works
A cruising boat plumbing system combines freshwater storage, pumps, hot water, drains, through-hulls and wastewater systems into one interconnected system. In this video, I walk through the plumbing design for my Albin 27 pocket trawler, including freshwater tanks, pressure pumps, accumulator tanks, a 10-gallon hot-water heater, PEX versus marine hose, through-hulls and seacocks. I also cover shower and sink drainage, why I chose a diaphragm pump instead of a conventional shower sump, and the differences between composting and electric marine toilets. Finally, I explain my choice of an electric macerating toilet connected to a black-water holding tank and how freshwater and waste-tank capacity affect long-term cruising.
Replacing and Installing Boat Thru-Hull Fittings
Thru-hull fittings are among the most critical components in a marine plumbing system because a failed fitting can potentially allow enough water into the hull to sink the boat. In this video, I replace undersized thru-hulls while rebuilding the head and galley plumbing on my pocket trawler. I cover choosing above- versus below-waterline fittings, installing polymer and bronze thru-hulls with marine sealant, adding backing blocks for support, and properly matching thru-hulls, hose barbs and plumbing hose sizes. The project demonstrates how careful sizing, alignment and installation of thru-hull fittings helps create a reliable drainage and plumbing system while reducing the potential for leaks and fitting failures.
Creating Plumbing Access Under a Boat Shower
Marine plumbing eventually needs maintenance, so access to drains, hoses and fittings should be designed into the boat before the shower is permanently finished. In this video, I modify the bathroom structure on my Albin 27 to create a dedicated access opening beneath the shower pan. I show how I determine where the plumbing needs to remain accessible, safely cut and modify the existing bulkhead, and plan the opening around the shower drain and surrounding structure. It’s a relatively small modification, but one that makes future shower drain, hose and plumbing repairs considerably easier without having to tear apart the finished bathroom.
Installing FRP Shower Panels in a Boat Bathroom
FRP panels provide a water-resistant, durable and easy-to-clean surface for finishing a shower inside a sailboat or pocket trawler. In this video, I install pre-cut fiberglass reinforced plastic (FRP) shower panels in the enlarged head of my Albin 27. I cover preparing the surfaces, applying FRP adhesive, fitting multiple panels into the confined bathroom space, installing trim pieces, and sealing the joints with silicone. I also show the correct installation sequence and techniques for avoiding trapped air, poorly bonded areas and excess adhesive. The project demonstrates a practical way to create finished waterproof shower walls as part of a complete DIY marine bathroom and plumbing system.
Installing FRP Shower Panels in a Boat Bathroom
FRP panels provide a water-resistant, durable and easy-to-clean surface for finishing a shower inside a sailboat or pocket trawler. In this video, I install pre-cut fiberglass reinforced plastic (FRP) shower panels in the enlarged head of my Albin 27. I cover preparing the surfaces, applying FRP adhesive, fitting multiple panels into the confined bathroom space, installing trim pieces, and sealing the joints with silicone. I also show the correct installation sequence and techniques for avoiding trapped air, poorly bonded areas and excess adhesive. The project demonstrates a practical way to create finished waterproof shower walls as part of a complete DIY marine bathroom and plumbing system.
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