Marine Pumps | Helpful Guide to Pumps Used On Boats

November 7, 2023 Published: January 26, 2021 1412

Marine pumps are an essential part of your boat’s plumbing system. The main purpose of most marine pumps is to move liquids from one point to another, including in and out of the boat.

We’ve created this helpful guide to help you understand the different marine pumps, and select the right pump for your onboard application.

The Freshwater Pump – Water Pressure System

Freshwater pumps deliver water to fixtures onboard, such as your sink and shower. Also known as pressurized water systems or water pressure pumps / systems, freshwater marine pumps make life onboard more comfortable by providing water “on tap” for your daily cleaning and showering applications.

Freshwater pumps are generally installed on all boats larger than runabouts and daysailers, where freshwater is both a convenience and a necessity.

What to look for in a Freshwater Pump

Here are some features of quality freshwater pumps you should be looking for:

Water-cooled motor
Integrated flow and pressure control
Quiet, pulsation free
Self-priming impeller system
Maintains constant, smooth input power
Adjustable Input power settings / variable speed
Dry run protection (runs dry without damage)
Services several outlets at once
Corrosion resistant, waterproof materials

Brands that Make Freshwater Marine Pumps

Washdown Pump – Washdown System

An onboard washdown pump provides a convenient means to hose down the deck after a day on the water. Clean up your cockpit after landing a big fish, rinse off the muddy anchor rode as it’s pulled up by the windlass, or rinse the decks off after scrubbing.

A complete washdown system includes the washdown marine pump with an integral pressure switch, a hose and nozzle, an inline filter, wiring, circuit protection and connectors.

What to look for in a Washdown Pump

Here are some features of quality washdown pumps you should be looking for:

Quiet and pulsation free, even at low speeds
Self-priming
Includes trigger nozzle, inline strainer and connections for hose
Both BSP and NPT connections
High pressure / high capacity
Max pressure shut off (50 – 60 PSI)
Corrosion resistant, waterproof materials

Brands that Make Washdown Pumps

Bilge Pumps

The primary job of most bilge pumps is to clear nuisance water from the bilges.

However, bilge pumps are also your last line of defense against sinking. This type of marine pump should be able to provide crucial extra time if your boat is taking on water, allowing to find and deal with the cause of the of the leak, or in more extreme situations, have enough time to don life jackets, hopefully keep your boat afloat long enough for help to arrive, or set up your own liferaft.

While the bilge pump that came up with your boat may be up to the task, most people upgrade to a larger bilge pump or add a backup bilge pump to be on the safe side.

What to look for in a Bilge Pump

Here are some features of quality bilge pumps you should be looking for:

Water-cooled motor
Motor sealed off by mechanical shaft seal or lipseal
High rate of head and flow
Universal base plate
Choice of 1-1/2” or 2” ports
Removable check valve
Corrosion resistant, waterproof materials
Removable impeller cover for easy clean out

Brands that Make Bilge Pumps

Livewell / Bait Tank Pump

Fishing livewells are used by fishermen to keep their bait alive until needed. Livewells are often used in commercial fishing applications as well as tournament fishing. Because tournament fishing encourages catch and release fishing, being able to keep a catch alive through the weigh in is important, and the livewell helps with this.

The heart of the entire system is the livewell pump. The livewell marine pump, also known as a bait tank pump, circulates freshwater into the livewell and some models also include an aerator so the fish or bait can continue breathing.

Some livewell pumps can also be used as washdown pumps.

What to look for in a Livewell Pump

Here are some features of quality livewell marine pumps you should be looking for:

Quiet and vibration-less
Thermally protected
Ignition protected (suitable for engine room installation)
Can run dry without damage
Adjustable pressure switch
Anti-airlock feature allows the pump to clear trapped air
Sealed switch and motor
Complete access to impeller for easy cleaning and maintenance
Aerator
Corrosion resistant motor and materials

Brands that Make Livewell Marine Pumps

Marine Air Conditioner Pumps

Marine air conditioning systems require special centrifugal pumps to provide a steady flow of cooling seawater or freshwater throughout the system at a consistent pressure.

The complete raw water marine air conditioning system consists of an intake through-hull fitting, seacock, strainer, marine air conditioner pump, and overboard discharge through-hull, all connected by hose or piping. Marine A/C pumps are designed to withstand the constant heavy-duty demands of marine air conditioning systems.

What to look for in a Marine Air Conditioner Pump

Here are some features of quality marine air conditioner pumps you should be looking for:

Water cooled
Magnetic drive (eliminates mechanical shaft seal wear, power-robbing friction, or leakage through the seal)
Submersible
Built-in overload protection
Ignition-protection
Can run dry without damage

Brands that Make Marine Air Conditioner Pumps

Macerator Pumps

Designed to fit into your boat’s plumbing, a macerator pump is a marine pump that breaks down solid waste so that it can easily be pumped out at designated pumping stations.

The function of the pump is to suction any solids and liquids from the lines connected to the holding tanks and grind it down to a small particle size for simple discharge of the waste. One major function of macerator pumps is to prevent clogged waste lines.

What to look for in a Macerator Pump

Here are some features of quality macerator marine pumps you should be looking for:

High capacity
Quiet
Capable of handling discharge from various types of plumbing, including sinks, bathtubs, toilets, washing machines and showers, including napkins, dental floss and other sanitary products

Brands that Make Macerator Pumps

Ballast Pumps

Ballast tanks are compartments on boats and larger ships that hold fresh or saltwater in order to balance the vessel and ensure stability. Older vessels used to use stone or iron to provide this balance, but have now been replaced by water which can be easily adjusted and is readily available.

Ballast pumps are marine pumps used to transfer large amounts of fresh or saltwater into the boat’s ballast tanks, or empty if necessary.

Ballast pumps are also used in wakeboard boats in order to create a larger wake by increasing the displacement and weight. This increases stability when wakeboarding. The wakeboard ballast system also reverses the tanks and empties the water in order to make the boat lighter and increase speed.

What to look for in a Ballast Pump

Here are some features of quality ballast pumps you should be looking for:

Ability to add or dump a significant amount of water ballast per minute
Dry run protection
Self-priming
Thermal overheat protection
Ability to monitor filling

Brands that Make Ballast Pumps

Desalination Pumps for Watermakers

A seawater desalination system is a facility for producing drinking water or service water from seawater. Many boaters carry desalination systems, or watermakers, onboard.

A seawater desalination system uses the principle of reverse osmosis in order to remove salt and other impurities from the saltwater, in order to create “potable” water — water that is safe to drink or use for food preparation.

The desalination pump on a watermaker is a marine pump that pushes the seawater at great pressures through a series of filters, which pull out all the salt and other contaminants.

What to look for in a Desalination Pump

Here are some features of quality desalination pumps you should be looking for:

Because of corrosive nature of saltwater, pump should be built out of stainless steel, titanium or nickel aluminum bronze (if used in brackish water)
Pump able to handle high pressure (made specifically for watermakers)
Corrosion resistant plungers

Brands that Make Desalination Pumps

Marine Pumps for Sale – Citimarine Store

We carry marine pumps for all the above mentioned purposes from all the major brands. Have a special task not outlined here? Contact us, and we’ll help get you situated with the pump you need as well. See all of the brands of marine pumps we carry, here: Marine Pumps

Have a good one!