The Connecticut boat plumbing guide.

Boat plumbing covers every system that moves water on, through, or off the boat. On most Connecticut boats that comes down to four separate systems, and they fail in four separate ways.

• The freshwater system. Stores potable water and delivers it under pressure to the galley, the head sink, and the shower.
• The waste system. Carries effluent from the marine head to a holding tank, and from the tank to a pumpout. This is the system Connecticut regulates.
• The bilge system. Keeps the inside of the hull dry by pumping out the water that always finds its way in.
• The watermaker. On the small share of boats that carry one, it turns seawater into fresh water. Most Connecticut boats do not need it.

The systems share hardware — hoses, pumps, through-hull fittings, sea cocks — and a plumbing problem can hide as an electrical one or the other way around. Helm covers the whole category and scopes the systems together rather than as four unrelated repairs.

A boat's freshwater system stores potable water in a tank and delivers it under pressure to every fixture on board. It is a closed loop with a handful of parts, and each one is a common point of failure.

• The tank. Usually polyethylene, sometimes aluminum or stainless, filled through a deck fill fitting and vented so it can breathe.
• The freshwater pump. A demand pump that runs when a tap opens and pressure drops, then shuts off when the system is back up to pressure. It draws on the boat's DC system.
• The accumulator tank. A small pressurized vessel that smooths the pump's output, so the pump does not switch on and off with every cup of water drawn.
• The water heater. Heated by the engine's coolant loop while underway, by a 120-volt element on shore power, or both.
• The lines. Flexible reinforced hose or semi-rigid tubing running to each fixture, plus a dockside connection on many boats that lets the system run on marina water without touching the tank.

Three problems account for most freshwater service calls. The first is a pump that short-cycles — switching on and off rapidly — which usually means a waterlogged accumulator, a small leak, or air in the lines. The second is weak or absent pressure, traced to a clogged inlet strainer, a tired pump, or an airlock. The third is water that tastes or smells wrong, which happens when water sits full and warm in the tank long enough to grow a biofilm. The fix for that last one is to drain, sanitize, and flush the tank and replace the filter. Because the pump is a steady DC draw, a freshwater fault and a battery fault can look alike, which is why the system belongs in the same picture as the boat's electrical and power systems.

On a Connecticut boat, any installed toilet must discharge to a Coast Guard-certified marine sanitation device, and because the state's coastal waters are a No Discharge Area, that effectively means a holding tank. No sewage, treated or untreated, may be put into the water.

Federal law sets the baseline. Section 312 of the Clean Water Act requires an operable, Coast Guard-certified marine sanitation device on any vessel with an installed toilet operating on United States navigable waters. There are three certified types:

• Type I. A treatment device that macerates and disinfects sewage, certified for vessels 65 feet and under.
• Type II. A larger biological treatment device, found mostly on commercial vessels rather than recreational boats.
• Type III. A holding tank that stores sewage on board until it can be pumped out ashore. No treatment, no discharge.

Connecticut narrows that further. The state has designated all of its coastal waters — from the Pawcatuck River at the Rhode Island line to the Byram River at the New York line, and out to the New York boundary — as a No Discharge Area. Inside that area, the discharge of any vessel sewage is prohibited, including effluent that a Type I or Type II device has already treated. That makes a Type III holding tank the only practical answer for a Connecticut boat. If a boat is plumbed with an overboard-discharge Y-valve, the valve has to be secured — wired or padlocked closed — so it cannot be opened in state waters.

Waste leaves the boat at a pumpout. Connecticut has roughly 90 pumpout stations and pumpout boats spread along the coast, the tidal rivers, and Candlewood Lake, and the state's Clean Vessel Act program makes pumpout free for recreational boaters at participating facilities. Connecticut DEEP publishes a map of every location and the full rules in its No Discharge Area program. Most marinas from Greenwich to Stonington have a pumpout on site or a pumpout boat that comes to the slip — one more thing worth checking when you read a slip contract at a Connecticut marina.

The waste system moves effluent from the head to the holding tank, and from the tank to a deck fitting where a pumpout empties it. It is a short run of plumbing, but it is the system owners complain about most, almost always because of odor.

• The head. A manual hand-pumped toilet or an electric one, flushed with raw water drawn from outside the hull or, on some boats, with fresh water from the tank.
• The holding tank. Sized to the boat, fitted with a vent so it can breathe as it fills and empties, and connected to a deck pumpout fitting.
• The vent. A through-hull fitting that lets the tank equalize pressure. A blocked vent is a leading cause of both pumpout trouble and cabin odor.
• The macerator. On some boats, a pump that grinds and assists the discharge to the deck fitting.

When a head smells, the cause is rarely the tank itself. The most common source is permeated sanitation hose. Over years, ordinary hose absorbs odor straight through its wall, and no amount of cleaning recovers it — the hose has to be replaced with proper marine sanitation hose. A blocked vent, an overfull tank, and dried-out hose seals fill out the rest of the list. Done right, with the correct hose and a clear vent, a marine head is close to odorless.

The bilge system keeps the inside of the hull dry by pumping out the water that inevitably collects in the lowest part of the boat. That water comes from a dozen ordinary sources: rain, spray over the deck, drip from the propeller shaft's packing gland, air-conditioning condensate, the occasional weeping fitting.

A bilge system has a few parts. One or more bilge pumps sit at the low point of the hull. A float switch turns each pump on when water rises and off when it drops. A panel switch gives the crew a manual override. And a high-water alarm — the part owners most often skip — sounds when water climbs past the level the pumps should be holding. ABYC, the standards body for recreational boats, calls for an audible high-water alarm on any boat with an enclosed accommodation compartment, with the alarm switch mounted just above the pump's float switch so it gives the earliest possible warning.

What the bilge system does not do is keep a sinking boat afloat. A recreational bilge pump is sized for nuisance water, not for a breach. A failed hose clamp, a cracked through-hull, or a split hose floods a hull far faster than any bilge pump can keep up — the pump buys minutes, not safety. The real protection is the alarm and the early warning it gives, especially for a boat sitting unattended in a slip. A monitored alarm that texts the owner the moment water rises is one of the most useful pieces of a vessel-monitoring setup, alongside the through-hull fittings and sea cocks a diver checks from the water.

Most Connecticut boats do not. A watermaker is a reverse-osmosis desalinator that turns seawater into potable water, and it earns its place on boats that spend long stretches away from a dock — offshore cruisers, liveaboards at anchor, and owners taking a boat down the coast for the winter. A boat that returns to its slip every weekend simply fills its tank at the dock and never needs one.

The system works by pressure. Pre-filters strip sediment from incoming seawater, then a high-pressure pump forces that water through a semi-permeable membrane at high pressure — commonly 800 psi and above. The membrane passes water molecules and rejects salt, and the leftover brine goes back overboard. The result is fresh, drinkable water made underway.

The thing to know about a watermaker is that it fails from disuse more than from use. Left idle, the organisms in the standing seawater inside it die and foul the membrane. A watermaker has to be run regularly, flushed with fresh water, and — for any long layup, which describes a Connecticut winter exactly — "pickled" with a storage biocide that keeps the membrane from spoiling. For the cruiser planning a longer passage it is worth the trouble; for most of the state's boats it is hardware they do not need.

Every plumbing system on a Connecticut boat has to be cleared of water before the freeze. Water expands by roughly nine percent as it freezes, and even a small amount trapped in a hose, a valve, or a pump chamber will crack the part holding it — a failure discovered only at spring launch, when the system is pressurized again.

The freshwater side comes first. Drain the tank and the water heater, run the lines until they are empty, then pump non-toxic propylene-glycol antifreeze through every tap and the shower until it runs pink. The antifreeze choice matters: automotive antifreeze is ethylene glycol, which is toxic and has no place anywhere near a potable water system. Only the non-toxic propylene-glycol product belongs on a boat.

The waste side is next. Pump out and rinse the holding tank at a pumpout, then winterize the head and its hoses with the same non-toxic antifreeze. Rinsing the tank first matters, because many holding-tank treatments are neutralized by antifreeze. Bilge pumps and their lines are drained, and a watermaker is pickled for the season.

None of this stands alone. Plumbing is one chapter of the boat's larger winterization, and every line is brought back, flushed, and pressure-tested in the spring as part of commissioning. Helm plans the two ends of the season as one scope, so no tap, tank, or pump is the thing that gets forgotten.

Plumbing is rarely the reason an owner calls — until a pump quits, a head will not stop smelling, or a bilge alarm goes off in a slip. It is steady, unglamorous work, and that is the part Helm takes on.

From a single inquiry, Helm:

1. Scopes the system. Freshwater pump, water heater, marine head, holding tank, sanitation hose, bilge pump, or high-water alarm — Helm confirms the boat and the existing hardware before any work is quoted.
2. Coordinates the right technician. A sanitation-hose replacement, a holding-tank repair, and a freshwater-pump swap are different jobs; Helm matches each to a technician who does that work.
3. Bundles the seasonal work. Winterizing every line in the fall and recommissioning it in the spring fold into the boat's wider seasonal scope.
4. Reads the whole boat. A pump that will not run can be a plumbing fault or an electrical one; a head that will not discharge can be a vent, a hose, or a macerator. Helm treats it as one picture rather than several separate calls.

Every job is scoped to the boat and comes back as a written proposal. Helm covers plumbing on boats kept on the coast from Greenwich to Stonington, on the Connecticut, Housatonic, and Thames rivers, and on the inland lakes.

Can you discharge a boat holding tank into Long Island Sound?

No. Connecticut's coastal waters are a federally designated No Discharge Area, which runs from the Pawcatuck River at the Rhode Island line to the Byram River at the New York line. Inside that area no vessel sewage may be discharged into the water, treated or untreated. All waste has to be retained on board and pumped out ashore at a pumpout facility.

Does a boat in Connecticut have to have a holding tank?

In practice, yes. Any boat with an installed toilet on United States navigable waters must have a Coast Guard-certified marine sanitation device. Because Connecticut's coastal waters are a No Discharge Area where even treated effluent may not be released, a Type III holding tank is the only practical choice. If the boat has an overboard-discharge valve, it must be secured closed so it cannot be opened in state waters.

Where can I pump out a boat in Connecticut?

Connecticut has roughly 90 pumpout stations and pumpout boats spread along the coast, the tidal rivers, and Candlewood Lake. The state's Clean Vessel Act program makes pumpout free for recreational boaters at participating facilities, and Connecticut DEEP publishes a map of every location.

Why does a boat's water smell or taste bad?

On the freshwater side, water that has sat full and warm in the tank grows a biofilm that taints taste and smell; the fix is to drain, sanitize, and flush the tank and replace the filter. A separate smell from the head is almost always permeated sanitation hose, which absorbs odor over years and has to be replaced, or a blocked tank vent.

Is a bilge pump enough to keep a boat from sinking?

No. A bilge pump is sized for nuisance water — rain, spray, packing-gland drip, air-conditioning condensate. A failed hose clamp or a cracked through-hull floods a hull far faster than any recreational bilge pump can keep up. The real protection is a high-water alarm that warns the owner early, which ABYC calls for on any boat with an enclosed accommodation compartment.

Does Helm coordinate boat plumbing in Connecticut?

Yes. Helm covers freshwater systems, marine heads and holding tanks, bilge pumps and high-water alarms, watermakers, and the seasonal winterizing and recommissioning of every line, for boats across Connecticut — the coast from Greenwich to Stonington, the Connecticut, Housatonic, and Thames rivers, and the inland lakes. One inquiry covers the whole category.