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How to choose the right wiper system for your boat

When it comes to safe boating, the wiper system on your boat is crucial. In this article, we present areas and components you need to be careful with when choosing wiper system for your boat.
The main reason why wipers are so important is so obvious, it can't be overseen: Good visibility. Bad visibility from your front or side window when raining or if you get a wave spray is the last thing that you need. A reliable and correct installed wiper system will enable you to keep the focus on navigation and maneuvering your boat.

The components of a wiper system

A complete wiper system consists of several components. And just like you don't want any weak link in a chain, you have to know that you can rely on each one of them. Selecting every component carefully will ensure a reliable performance of the system as a whole.
  1. Wiper motor
  2. Wiper arm
  3. Wiper blade
  4. Wiper controller
  5. Washing system

Selecting wiper motor, arm and blade

When selecting the right wiper motor you always start from the size and shape of your window. The larger the window, the longer arm and blade you will need. Since longer arms and blades will create more friction on the window, you will also need a more powerful wiper motor that can handle the increased torque.
In order to get the best configuration, you need to consider three different options of the sweep. Each sweep has its own arm style.
standard-arm Standard arm with the motor mounted in the middle of the window
standard-arm Pantograph arm with the motor mounted in the middle of the window
In case you cannot mount the motor in the center of the window or if this sweep pattern is more suitable for your application there is a third option.
standard-arm Arm with adjustable tip and motor mounted off-center


Measure your window and determine where the shaft of the wiper motor will be placed. In most cases, you want to mount the motor in the middle of the window above or below. Always aim to get your line of sight in the center of the sweep (if you choose one of ROCA's wiper systems, you can change the sweep angle and parking position very easily). The distance from the shaft to the center of the sweep will give you the arm length. With the arm length you can now go on and select the most suitable wiper motor.
ROCA has several wiper systems based on the maximum torque in Nm (Newton-meter) on the driving shaft and the maximum length of arm and blade combination. Please note that the W12 wiper is the only wiper motor that is water-resistant.
Model Max Torque Max arm length Max blade length
W5 5 Nm 355 mm / 14” 355 mm / 14”
W10 10 Nm 610 mm / 24” 560 mm / 22”
W12 12 Nm 610 mm / 24” 560 mm / 22”
W25 25 Nm 750 mm / 30” 750 mm / 30”
W38 38 Nm 900 mm / 35” 900 mm / 35”
W50 50 Nm 1200 mm / 47” 1200 mm / 47”
Based on your window size you might have to add another wiper on the side. Make sure that your sweeps are separated and not overlapping. Overlapping sweeps can cause the arms to collide causing total system damage.
Dual standard arms Dual standard arms
dual-arms-adjustable Dual arms with adjustable tip
Dual-pantograph Dual pantograph arms
Wiper blades come in fixed lengths ranging from 280mm / 11” to 1016 mm/ 40”. Always aim for the longest blade possible to get as much clean window as possible.

Wiper control systems

The easiest way of operating one wiper is with just a simple on/off switch. With this type of switch you are able to turn the wiper on and off and get it to park - but you can only use one speed. You will not be able to use any extra features that a wiper might provide - like fast speed, washing, intermittent sweep or synchronization between wipers.
For more features on your wiper you must install a more advanced switch like ROCA's watertight switches 466208 (W12) or 466222 (W25, W38 , W50). With these switches you will be able to use slow speed, fast speed and parking.
To enable all features on your wipers you will need to use a wiper control. With a wiper control you will get slow and fast speed, intermittent sweep and washing. If you have more than one wiper in your system the wiper control will also give you synchronization between the motors. You can choose to operate the wiper system with a single switch that will control all the wipers in your system but you can also go for a more advanced solution with a full feature wiper panel. The wiper panel will enable you to operate each wiper motor individually.


It's more and more common to have washing installed on your wiper system. The washing will help to rinse the window from salt spray, pollen or dust. Your washing system can run on pressurized water from your boat's freshwater system or you can install a stand-alone tank with a DC pump.
Most of ROCA's wiper arms come with spray nozzles pre-installed directly on the arm where the water is needed. For W12 and W10 arms you need to purchase the spray nozzle separately. To complete the installation, you will also need a bulkhead feedthrough and maybe some extra hose.


When choosing a wiper system for your boat, you need to take all components into account. The size and the shape of your window will set the limits for the motor, arm and blade. 
If you want to learn more about wiper systems and how ROCA's products can be adjusted to different window sizes, shapes and models, please download our product presentation (click on the button below).

Product Presentation


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