Bilge pumps
Articles

Boating and Marine Pumps

An essential piece of equipment for every vessel is a bilge pump because if the integrity of your vessel becomes compromised then your bilge pump, if it is the right one, will give you the best possible chance of staying afloat. Boathut stock a selection of pumps that offer the boating public a comprehensive range to choose from. Brands we stock include Whale, Attwood, TMC and Henderson, these are the leading brands that boast years of history in the boating industry. Their pumps are renowned for their longevity and problem free operation.

Manual Pumps

As their name suggests, are a manual operated pump that requires the water to be physically pumped out. They can move large quantities of water however they require substantial effort from the operator.
Manual pumps are an ideal companion to you electric models standby failsafe in the event of your electrics failing.

 

Centrifugal Pumps

The most common and well established model of pump, these are high capacity electrical pumps that rely on a “wheel” driven by a shaft to pump the water. These are a popular pump and can move a lot of water quickly. A big plus with Centrifugal pumps is that they are able to run without water for short periods of time without doing any immediate damage to the pump.

 

Diaphragm Pumps

These pumps move fluid by making use of a membrane that increases and decreases the volume of a pumping chamber. They draw the fluid in and push it out through a set of one-way check valves. They are a self–priming pump which is a big plus. But they do require a strainer on the intake side as any form of debris that can inhibit the performance of the pump.

 

Automatic Pumps

These pumps operate automatically and are dependent on some form of switch mechanism to start the pump. These switches can be in the form of either a float switch or an electronic sensing switch. These pumps regulate the level of water in your boat automatically but still need to be checked periodically as your vessel may experience a leak that could be getting worse over time and eventually overtake the pumps capacity.

 

Float Switch

A switch that engages an automatic pump. It works on the level of water in the vessels bilge, as the water level increases to a point that is above the float on the switch it will engage your pump. Once the level of the water decreases below that of the float it will automatically switch off the pump.

 

Electronic Sensor Switch

A switch that automatically switches your pump on or off by sensing the presence of water through the plastic housing. The good thing about these switches is that they have no moving parts so wear and tear is not an issue.
There are  a number of different types of pumps and manufacturers. However, the most important part of selecting a pump is to choose the correct model for your vessel. The size, model and build of your boat will help determine which pump is right for you.

 

Boat Size

All electric bilge pumps are rated according to how much water they can move. This unimpeded flow rate is measured in gallons per hour or gallons per minute. The size of the pump that you choose will generally depend on the size of the boat that you own; but don’t fall into the trap of thinking that a small boat only needs a small pump. Lower sides and smaller compartments mean that they are affected a lot quicker by water ingress. Fitting an oversize pump is a very good idea.

 

In small to medium sized powered vessels:
Vessel size:
under 18 feet - 300 to 500 gallons per hourunder 5.5 metres - 1135 to 1892 litres per hour
18 to 23 feet - 450 to 700 gallons per hour5.5 to 7 metres - 1703 to 2649 litres per hour
22 to 26 feet - 100 to 1100 gallons per hour 7 to 7.9 metres - 378 to 4163 litres per hour
In larger Powerboats:
As your vessel size increases you would need to look at the addition of a manual pump as well as your electrical pump. This will give you peace of mind if your electrical pump fails, you will still be able to pump the water out manually. If your vessel has severalcompartments in, then fitting a pump to each compartment can be a very good idea. Its always better to have too many pumps than too few!
Vessel size:
26 to 30 feet - 800 to1200 gallons per hour7.9 to 9.1 metres - 3028 to 4542 litres per hour
30 to 35 feet - 1000 to 1600 gallons per hour 9.1 to 10.7 metres - 3785 to 6056 litres per hour
35 to 40 feet - 1600 to 2200 gallons per hour 10.7 to 12.2 metres - 6056 to 8327 litres per hour
40 to 45 feet - 2000 to 4000 gallons per hour 12.2 to 13.7 metres - 7570 ot 15141 litres per hour
In Sail Boats:
Sailing boats can fall into another category altogether as they can list steeply while under sail, their bilges can be a lot deeper thanstandard vessels; and they can operate in rougher conditions than most other boats. Due to these facts, multiple pumps as well as amanual standby pump would be a good idea.
Vessel size:
22 to 26 feet - 600 to 800 gallons per hour6.7 to 7.9 metres - 2271to 3028 litres per hour
26 to 30 feet - 800 to 1000 gallons per hour7.9 to 9.1 metres - 3028 to 3785 litres per hour
30 to 35 feet - 1000 to 1600 gallons per hour 9.1 to 10.7 metres - 3785 to 6056 litres per hour
35 to 40 feet - 1600 to 2200 gallons per hour 10.7 to 12.2 metres - 6056 ot 7570 litres per hour
40 to 45 feet - 2000 to 4000 gallons per hour 12.2 to 13.7 metres - 7570 to 15141 litres per hour

Installation hints:

  • Always ensure that you stick to the manufacturers recommendations with regards to wire grades and thicknesses
  • Keep discharge hoses as short as possible
  • Use smooth bore hoses – corrugated hosing can affect the performance of your pumps
  • Use vented loops if the thru hull fitting on the outlet side can be submerged, for example on sailboats that heel over while under sail

Technical information source: BLA.com.au Boating Lifestyle Adventure

 

One thought on “Boating and Marine Pumps

  1. Jim M says:

    Very informative! My knowledge on Boat Pumps has increased when I read this article!

Leave a Reply

Your email address will not be published. Required fields are marked *