What type of bilge pump should I choose for my boat?
The installation of a dewatering device in the hold of a boat is compulsory for comply with regulations in force. Most boats these days come standard with a manual or automatic bilge pump. On a sailboat and some types of pleasure craft, the flow rate of the bilge pump originally installed is not sufficient in the event of a major waterway. The best precaution to take is thus to double this equipment. What are the parameters to remember when installing a bilge pump? Why choose a particular pump model in particular? What type of bilge pump to choose? Which brand of pump should be preferred? Find out the answers to all these questions later in the article.
The parameters to be studied before installing a bilge pump
The main function of a bilge pump, as the name suggests, is to remove water from a boat's bilge. It exists two main categories of bilge pumps : mechanical bilge pumps and electric bilge pumps. The choice of one or the other category depends on the type and size of a boat. If you opt for a manual pump, be aware that the flow is always low. On the other hand, if your choice is an electric model, the flow rate depends on the power of the pump motor and that of your boat's battery. Before asking what type of bilge pump to choose, you should study its location and the space available.
Why choose a manual siphon bilge pump?
Successful boat maintenance involves the use of the right equipment. Even on small open boats, it is now more practical to use a small hand pump instead of drawing and draining water from the bottom with a bailer. The manual siphon bilge pump is not a substitute for the boat bilge pump. It is, in fact, a very light, inexpensive model which does not require any maintenance. This type of bilge pump is mainly used in boat cleaning. the operation of a bilge pump siphon is quite simple because it is a large syringe that draws water from its end and releases it through a hose. Its greatest advantages lie in its light weight and its great functionality when it comes to drying the bilge of the boat. The main drawback is obviously its low flow.
See an efficient siphon bilge pump.
Why choose a diaphragm fixed manual bilge pump?
On a non-self-draining boat which is not equipped with a bilge pump, it is recommended to attach a fixed diaphragm manual bilge pump. Having a flow rate of between 25 and 100 liters per minute, equipment of this kind is mainly used to wash a boat ... If you are looking for a bilge pump for semi rigid, there are more powerful models that you can use as a back-up device. Affordable and easy to install, fixed diaphragm manual bilge pumps are low maintenance. If you are wondering what type of bilge pump to choose, know that a model of this kind is ineffective in dealing with a major waterway.
See The Best Fixed Diaphragm Manual Bilge Pumps:
-OSCULATI diaphragm bilge pump
Why choose a submersible electric bilge pump with manual actuation?
A manually operated submersible electric bilge pump is best suited for small boats. This type of pump is less expensive than an automatic model and maintenance is limited to replacing the filter during winter storage. You just need to activate the bilge pump trigger installed in the cockpit or on the deck to evacuate the water.
You will find in the table below the submersible electric bilge pumps (manually operated) that we recommend according to their flow:
| Model | Maximum delivery height | Debit | Recommended fuse | Outlet diameter |
|---|---|---|---|---|
| ATTWOOD TSUNAMI 12V T500 | 2,4m | 500 GPH or 1 to 500 L / h | A 3 | 19 mm (3/4 ") |
| RULE 12V BILGE PUMP | - | 800 GPH or 3 L / h | - | - |
| SEAFLO 12V BILGE PUMP | 4,5m | 1100 GPH or 3 to 500 L / h | A 5 | 29 mm (1 1/8 ″) |
Why choose an automatic electric bilge pump?
It should be noted that the regulations on the bilge pump do not require the installation of an automatic bilge pump. However, installing a self-priming electric bilge pump optimizes the safety of the boat (too many boats have sunk in port!). Indeed, a float integrated in the structure of the pump triggers the motor automatically when the water in the bilge reaches a certain level. The price of this type of pump is more expensive compared to an electric submersible bilge pump. As for maintenance, the components of the automatic release must be checked regularly so that the equipment is always ready in the event of a water leak.
You will find in the table below the automatic bilge pumps that we recommend according to their flow:
| Model | Maximum delivery height | Debit | Recommended fuse | Outlet diameter |
|---|---|---|---|---|
| SAHARA 12V ATTWOOD S500 | 2,4m | 500 GPH or 1 to 500 L / h | A 3 | 19 mm (3/4 ") |
| SEAFLO 12V AUTO BILGE PUMP | 2,5m | 750 GPH or 2 to 500 L / h | A 6 | 19 mm (3/4 ") |
| SAHARA 12V ATTWOOD S1100 | 2,7m | 1100 GPH or 3 to 500 L / h | A 6 | 29 mm (1 1/8 ″) |
| RULE LoPro 900S (for tight spaces) | - | 56 L / min | - | - |
NB: In some cases, the space available will be decisive in the choice of automatic bilge pump. For example, if your bilge is very narrow, opt for the automatic bilge pump RULE LoPro 900S. It is only 60mm high and is triggered from 3,25cm or 5cm of water. It can be mounted horizontally or vertically to adapt to the hold of any boat.
Our opinion on which type of bilge pump to choose
We strongly advise motor boat and sailboat owners to equip themselves with two systems: an electric bilge pump and a fixed manual bilge pump. Indeed, if the electric bilge pump no longer works, you must always have a plan B. In addition, we recommend choosing an automatic electric bilge pump rather than an electric submerged manual. In our eyes, the price difference is justified when we know the statistics of the boat sunk at their anchorage ... Nevertheless, for this to be effective, it is imperative to couple your system with an alarm so that you have time to intervene before the battery is dead.
Note that if you already have a submersible bilge pump you can easily convert to automatic pump. This is possible thanks to a automatic switch (also called trigger float or water level sensor). Choose a contactor suitable for your bilge pump. The three automatic contactors below are all non-toxic and mercury-free:
Finally, replace your bailer by purchasing a portable manual bilge pump. They're small, inexpensive, and make your life a lot easier every time you clean the bilge.
The choice of bilge pump flow according to the length of your boat
Flow is an important factor in determining what type of bilge pump to choose:
- For a boat ranging from 3,5 to 5 m in length, the connection of an automatic bilge pump having a flow rate of around 1900 l / hour is required.
- Beyond 5 m to 7 m, you need a minimum flow rate of 3 l / hour.
- For a boat ranging from 7 m to 9 m, the installation of an automatic bilge pump with a flow rate exceeding 4 l / hour is recommended.
- For boats over 9m, you will have to choose a 12 v high flow bilge pump (or 24 v). In addition, it is recommended to install several autonomous bilge pumps distributed in different places of your vessel. We recommend having at least two heavy duty pumps. The most powerful bilge pump will need to be positioned under the engine or in the sump.
Obviously, you must also take into account the necessary delivery height and the space available in the bilge to determine the most suitable pump for your boat.
It is best to always oversize your pumps if you have enough space in your bilge and your electrical installation can support them. To give you an idea, a waterway created by a 12cm hole below the waterline generates a water inlet of 7200l / h, or 1900 GPH.
You will find in the table below the high flow bilge pumps that we recommend according to their flow. Their delivery height is between 5 and 6m (and up to 8m for the Osculati Maxi). However, these pumps are all electric submersible bilge pumps (manually operated). We therefore recommend converting them to an automatic pump using a automatic switch (see the previous paragraph).
| Model | Debit |
|---|---|
| Rule Heavy Duty | 1500GPH |
| Attwood Heavy Duty | 1700GPH |
| Rule Heavy Duty | 2000GPH |
| SeaFlo Heavy Duty | 3000GPH |
| Maxi osculati | 3500GPH |
| Rule Heavy Duty | 3700GPH |
| Maxi osculati | 4700GPH |
NB: these pumps must be installed with a fuse of up to 25A or more! For more details, read our article ''What fuse to use on a boat bilge pump?'.
Which brand of bilge pump to choose?
The bilge pump market is dominated by newer models of equipment, which makes the choice quite difficult. That is why we have selected from the tables in this article the best bilge pumps for each type of pump and each flow rate. Be aware, however, that the most famous brands like Attwood, Seaflo and Rule offer a wide range of products. If you plan to install a bilge pump kit from another brand such as Johnson Pump, Whale, Nuova Rade, Plastimo, Jabsco, Osculati and others, take care to consult the opinions on e-commerce sites to know the reliability, efficiency and performance of certain models . This will help you confidently determine what type of bilge pump to choose.
Once you have made your choice, you can consult our article: How to install a bilge pump on a boat?
What essential accessories to choose for a bilge pump?
- All electric bilge pumps (automatic or manual) must be connected to a switch on the instrument panel. This switch is never included with the pump. We recommend SeaFlo 3-position switch (auto / manual / off) which is fine.
- Bilge pumps are delivered without their fuses. Preferably avoid "glass" fuses and "soapstone" fuses as they oxidize too quickly. The best fuses for bilge pumps are jumper type fuses. Finally, don't forget to buy the corresponding fuse holder.
- There is no point ininstall two bilge pumps on the same discharge line, they will not work better than one. Always install a through-hull for each pump. Choose the through-hull with a diameter suitable for your delivery pipe (see shell passes of different diameters here).
- Opt for small size delivery hoses, to reduce their resistance and optimize the bilge pump flow. Prefer 25 mm pipes for small and medium-sized pumps, and 38 mm for more powerful models.
See an efficient 25mm discharge pipe.
See a good 38mm discharge hose.
- Finally, your bilge pump motor may fail at the least opportune moment ... We therefore recommend that you have spare parts. On some models like Attwood Tsunami pumps, you only need to buy replacement cartridges to change the motor without having to touch the pump mount or the plumbing. They are easily clipped and unclipped:
See ATTWOOD TSUNAMI T500 spare cartridges
See ATTWOOD TSUNAMI T800 spare cartridges
See ATTWOOD TSUNAMI T1200 spare cartridges
You will find many spare parts for other brands on Amazon, Ebay et Ticketmaster.
Learn more about boat bilge pumps:
How to test a bilge pump on a boat?
What fuse to use on a boat bilge pump?
